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Management breaks the natural productivity-biodiversity relationship in forests and grassland： an opinion

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Forest Ecosystems 2018年第1期5卷 28-35页

作者： e.d.schulze o.bouriaud u.weber c.roscher d.hessenmoeller f.kroiher p.schall mpi biogeochemistry Box 10016407701 JenaGermany national forest inventory national research and development institute for forestry incdsErolor Bd 128VoluntariRomania and University stefan cel Mare of Suceava13 Universitatl Str.720229 SuceavaRomanla ufz hemholtz centre for environmental researchphysiological diversityDiversityPermoserstr 1504318 Lelpzig Germany forstamt schmalkalden thueringen forstSchlossberg 1198574 Schmalkalden Germany thünen-institut für waldokosysteme Adolf Moller Str 11 6225 EberswaldeGermany department silviculture and forest ecology of the temperate zones university of gottingenD 37077 GOttingenGermany

Background： Two approaches mark the difference between the ＂ecological＂ and ＂agricultural＂ view of the biodiversity/ growth relation. In ecology the trend is averaged by taking monocultures of all species as baseline to evaluate mixtures. This contrasts the ＂agricultural＂ view focusing on the most productive species or species combination as baseline to evaluate mixtures. The present study investigates the change of highest rates （maximum） productivities in grasslands and forests with increasing plant （or tree） diversity, and compares these with the average response. Methods： We base our analysis on existing published datasets relating the growth of plant stands （growth rate per land area） to the diversity on the same plot. We use a global dataset （Ellis et al. 2012 and MODIS-data, see Fig. 1）, the grassland experiment in lena （Buchmann et al. 2017）, the regional study on forests in Romania and Germany by Bouriaud et al. （2016）, and data from the German National Forest inventory （BWl 3, see Fig. 3）. In all cases the average response of growth to changes in biodiversity as well as the boundary line of the maximum values was calculated. Results： in both vegetation types a decreasing trend of maximum productivity with any added species emerges, contrasting the average trend that was positive in grassland, but absent in forests. The trend of maximum values was non-significant in grasslands probably due to the fact that not all combinations of species mixtures were available. In temperate forests, maximum productivity decreases significantly by about 10% in regional studies and by 8% at national scale with each added species. Maximum biomass per area was the same for managed and unmanaged conditions. A global assessment of NPP and biodiversity could also not confirm a general positive biodiversity- productivity relationship. Conclusions： Managed grasslands and forests reach highest productivity and volumes at low diversity. Also globally we could not confirm a biodiversi

关键词： Biodiversity Productivity Maximum rates Land management Forests Grasslands

Numerical Simulation of Mechanical Properties of Nano Particle Modified Polyamide 6 via RVE Modeling

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Journal of Materials Science and Chemical Engineering 2015年第1期3卷 95-102页

作者： J. Huang M. uhrig u. weber S. Schmauder Institute for Materials Testing Materials Science and Strength of Materials University of Stuttgart Stuttgart Germany

In this paper the physical influences on the mechanical behavior of a Polyamide 6 (PA 6)/Mont- morillonit (MMT)-nanocomposite are examined by a selected structure modification in a numerical parameter study. Experimental data of tensile tests of three different volume fractions at ambient temperature are used as reference. These were compared to homogenized stress-strain curves calculated with 3D representative volume elements (RVE) under periodic boundary conditions, in which the curve areas are considered until the tensile yield strength is reached. Besides the influence of filler orientation, exfoliation and its volume fraction, both adhesive interface behavior between the filler and matrix, and local partially crystalline interphases around the MMT-plates were also taken into account. A good approximation of the numerical representation of the experimental curves was achieved only after the introduction of the 30 - 40 nm thick partially crystalline interphases with higher stiffness and strength around the MMT-plates. The use of an exclusively isotropic matrix led to an underestimation of the mechanical values. The local modifications of the morphology were assumed to be transversely isotropic both in the elastic and in the plastic region. The transverse plane is defined by the lateral particle surface. Compared with the experimentally determined values of the corresponding Young’s Modulus, an excellent correlation was achieved. The yield strength for the largest volume fraction shows the best agreement with experimental values.

关键词： PA 6 Nanocomposite RVE Modeling Mechanical Properties

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中国大陆科学钻的裂变径迹数据及其地质解释

中国大陆科学钻的裂变径迹数据及其地质解释

第九届全国固体核径迹学术研讨会

作者：刘顺生 u.Glasacher 许志琴 u,weber G.Wagner 中国科学院广州地球化学研究所 Max-Planck-Institut für Kemphysik D-69029 Heidelberg Geologisch-Palontologisches InstitutRuprecht-Karls Universitt Heidelberg D-69120 Heidelberg 中国地质科学院地质研究所 Max-Planck-Institut für Kernphysik D-69029 Heidelberg

通过对中国大陆科学钻(CCSD)主孔(MH)和先导孔(PP-2)的裂变径迹分析,初步揭示了钻孔地区超高压变质体折返后期的构造热历史。裂变径迹年龄值总的变化趋势是随钻孔深度的增加而逐渐减少。地表样的磷灰石裂变径迹年龄87．1Ma 左右,1,148m...

通过对中国大陆科学钻(CCSD)主孔(MH)和先导孔(PP-2)的裂变径迹分析,初步揭示了钻孔地区超高压变质体折返后期的构造热历史。裂变径迹年龄值总的变化趋势是随钻孔深度的增加而逐渐减少。地表样的磷灰石裂变径迹年龄87．1Ma 左右,1,148m 深处为40．0Ma,2,800m 深处为 20．0Ma,至3,899m 深处则为3．2Ma,超过4,000m 深度以后,磷灰石裂变径迹年龄趋近于零。表明地壳温度随深度的增加而增加的规律,且超过4,000m 的深度以后,地温已超过磷灰石保存裂变径迹的临界温度.从裂变径迹的系统分析得知,除以上总的变化趋势以外,裂变径迹年龄值还存在约千异常变化,结合钻孔的岩心构造剖面,文中对该区的构造热历史进行了初步探讨.

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聚焦习惯:运用行为学理论减少碳排放

博鳌观察 2014年第3期 70-72页

作者：埃尔克·韦伯(Elke u weber) 露丝·格林斯潘·贝尔(Ruth Greenspan Bell) 永年哥伦比亚大学商学院Jerome A.Chazen国际商学院伍德罗威尔逊国际研究中心不详

人为的气候变化已悄然渗透至全人类的生活。作为能源消耗持续增加的后果,这种情况最初出现在西方国家,最近已成为全球性现象。无论我们居住在城市还是遥远的森林,能源几乎融入了生活的每一部分。大部分气候变化问题的＂解决方案＂都倾... 详细信息

人为的气候变化已悄然渗透至全人类的生活。作为能源消耗持续增加的后果,这种情况最初出现在西方国家,最近已成为全球性现象。无论我们居住在城市还是遥远的森林,能源几乎融入了生活的每一部分。大部分气候变化问题的＂解决方案＂都倾向于＂大爆炸理论＂,即诉诸全方位立法和全球性协议。这种理念假设,人类的任务就是制定正确的政策。

关键词：行为学理论气候变化能源消耗爆炸理论碳排放国际条约 silver 西方国家行为学研究气体排放

Charged particles:unique tools to study irradiation resistance of concentrated solid solution alloys

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Journal of Materials Science & Technology 2023年第9期140卷 260-276页

作者： Yanwen Zhang Lumin Wang William J.weber Materials Science and Technology Division Oak Ridge National LaboratoryOak RidgeTN37831USA Department of Materials Science&Engineering University of TennesseeKnoxvilleTN37996USA Department of Nuclear Engineering and Radiological Sciences University of MichiganAnn ArborMI48109USA

Many multicomponent concentrated solid solution alloys(CSAs),including high-entropy alloys(HEAs),exhibit improved radiation resistance and enhanced structural stability in harsh *** study and assess irradiation resistance of nuclear materials,energetic ion and electron beams are commonly used to create displacement ***,charged particles of ions,electrons,and positrons are unique tools to create and characterize radiation *** beam analysis(e.g.,Rutherford backscattering spectrometry,nuclear reaction analysis,and time-of-flight elastic recoil detection analysis),electron microscopy techniques(e.g.,transmission or scanning electron microscopy,and electron diffraction),and positron annihilation spectroscopy have been applied to characterize irradiated CSAs or HEAs to understand defect formation and evolution together with chemical and microstructural *** distinctive analyzing power and some perspectives in these techniques are *** developing structural alloys desirable for applications in advanced reactors,neutron exposure is a critical test but the limitation in achievable high damage levels is,however,a *** irradiation is often used as a surrogate for neutron irradiation,and the associated reduced transmutations and higher displacements per atom(dpa)rates are desirable for materials ***,cautions need to be taken when relying on ion irradiation results for reactor *** on differences between ions and neutrons is briefly *** addition,the links to bridge the current advances on fundamental understandings to reactor applications are discussed to lay the groundwork between neutrons and ions for radiation effects studies.

关键词： chemical disorder high-entropy alloys chemically complex alloys charged particles radiation resistance displacement damage electronic energy loss and ionization transmutation

ON　THE　BOuNDED　AND　uNBOuNDED　SOLuTIONS　OF　ONE　DIMENSIONAL　NONLINEAR　REACTION－DIFFuSION　PROBLEM

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Chinese Annals of Mathematics,Series B 1995年第2期16卷 245-254页

作者： GEWEIGAO R.O.weber DeparrnetofMathematics BeijingInstituteofTechnologyBeijing100081China DepartmentofMathematics UniversityCollegeADFACanberraACT2600Australia

The existence of bounded and unbounded solutions to nonlinear reactinn-diffusion problemut = △Φ(u) + F(u,x,t) with initial or initial-boundal conditinns is discussed when u=u(x, t), x ∈ R. Simple criteria are given.

关键词： Reaction-Diffusion equation Bounded solution Cauchy problem.1991 MR Subject Classification 35K57.

Biological soil crusts as an integral component of desert environments

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Ecological Processes 2013年第1期2卷 116-129页

作者： Jayne Belnap Bettina weber Department of Archaeology Simon Fraser UniversityBurnabyBC V5A 1S6Canada Department of Biology Plant Ecology and SystematicsUniversity of KaiserslauternP.O.Box 3049Kaiserslautern 67653Germany Multiphase Chemistry Department Max Planck Institute for ChemistryHahn-Meitner-Weg 1Mainz 55128Germany

The biology and ecology of biological soil crusts,a soil surface community of mosses,lichens,cyanobacteria,green algae,fungi,and bacteria,have only recently been a topic of *** efforts began in the western u.S.(Cameron,Harper,Rushforth,and ***),Australia(Rogers),and Israel(Friedmann,Evenari,and Lange)in the late 1960s and 1970s(e.g.,Friedmann et al.1967;Evenari 1985,reviewed in Harper and Marble 1988).However,these groups worked independently of each other and,in fact,were often not aware of each other’s *** addition,biological soil crust communities were seen as more a novelty than a critical component of dryland eco*** then,researchers have investigated many different aspects of these communities and have shown that although small to microscopic,biological soil crusts are critical in many ecological processes of *** often cover most of desert soil surfaces and substantially mediate inputs and outputs from desert soils(Belnap et al.2003).They can be a large source of biodiversity for deserts,as they can contain more species than the surrounding vascular plant community(Rosentreter 1986).These communities are important in reducing soil erosion and increasing soil fertility through the capture of dust and the fixation of atmospheric nitrogen and carbon into forms available to other life forms(Elbert et al.2012).

关键词： soil fertility component

Minimum spouting velocity of flat-base spouted fluid bed

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Particuology 2018年第1期16卷 27-36页

作者： Esmail R. Monazam Ronald W. Breault Justin weber Ky Layfield National Energy Technology Laboratory U. S. Department of Energy 3610 Collins Ferry Rd. Morgantown WV26507-0880 USA REM Engineering Services PLLC 3537 Collins Ferry Rd. Morgantown WV26505 USA

Experiments were performed on spout characteristics of a cylindrical spout-fluidized bed （I.D. = 10 cm） with different static heights and two materials （A1203 and high density polyethylene）. Results of minimum spouting velocity obtained in this study were compared with reported correlations for both spouted and spout-fluidized beds. Considerable discrepancies were found between the values obtained using different model equations as well as with respect to experimental results. Based on the Mathur-Gishler correlation, a new correlation is proposed for calculating the minimum spouting velocity that introduces the ratio u/umf. It was found that the minimum spouting velocity decreases with increasing fluidizing gas velocity （u/umf）. The pressure drop at the point of minimum spouting velocity is also correlated using this dimensionless group and is presented in this work. This investigation demonstrates that the use of correlations reported in the literature that focus primarily on conical bottom spouted beds are not applicable to fiat-bottom spouted and spout-fluidized beds.

关键词： Spouted bed Spout-fluidized bed Minimum spouting velocity Flat-bottom spouted bed

Progressive <I>β</i>Cell Failure in Type 2 Diabetes Mellitus: Microvascular Pancreatic Isletopathy?

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Journal of Diabetes Mellitus 2015年第1期5卷 21-27页

作者： udaya M. Kabadi Mary u. Kabadi Sommany weber Aaron Bubolz Edward Finnerty university of Iowa Carver College of Medicine Iowa City Iowa USA VA Medical Center Phoenix Arizona USA Des Moines university Des Moines Iowa USA

Background: uKPDS suggested relentless deterioration of β cell function as a part of natural course of type 2 diabetes mellitus. However, the course was apparently not universal since many patients maintained glycemic goal (HbA1c β cell failure occurred around the same time as the time of onset of microvascular complications. Finally, the exact mechanism of progressive β cell failure remains to be defined. It is plausible that β cell failure may be due to fibrosis of pancreatic islets secondary to microangiopathy since no organ or tissue is exempt from this complication. Objective: To assess epidemiologic correlation between presence of b cell failure and microvascular complications by determining the prevalence of β cell failure in subjects with type 2 diabetes with increasing number of known microvascular complications. Methods: 650 Subjects with ages 40-75 years and duration of DM 4-23 years were divided into 4 groups according to number of microvascular complications, e.g. retinopathy, nephropathy, and neuropathy. β cell failure (β -?ve ) is defined as HbA1c > 7.0% with any therapy or HbA1c β cell function is deemed “preserved” (β + ve) with HbA1c b cell failure progressively rose with increasing number of microvascular complications from 0 to 2 with no further significant rise with 3 complications whereas subjects with preserved β cell function declined with increasing number of microvascular complications (p β cell failure (p β cell failure/β cell preserved with increasing number of microvascular complications as well as the greater duration of Diabetes. However, a significantly (p β cell failure persisted for rising number of microvascular complications even after eliminating the influence of age and duration of diabetes. Conclusion: β cell failure may be a manifestation of microvascular pancreatic isletopathy similar to other microvascular complications.

关键词： Type 2 Diabetes Beta Cell Failure Pancreatic Isletopathy