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人类环境杂志 1997年第6期26卷 374-378页

作者： JohnW.Reid richard e.rice 石培礼哈佛大学约翰.F.肯尼迪政府学院密歇根大学的自然资源与环境学院

在过去几年间,人们在协调保护与发展议程方面已作了许多努力,很多保护机构信奉的观点是从天然林中精心利用木材资源才是可行的保护对策的组成部分。遗憾的是,"天然林管理"的投资在财政上缺乏吸引力,政府通常不愿意或难以督促采伐者进行... 详细信息

在过去几年间,人们在协调保护与发展议程方面已作了许多努力,很多保护机构信奉的观点是从天然林中精心利用木材资源才是可行的保护对策的组成部分。遗憾的是,"天然林管理"的投资在财政上缺乏吸引力,政府通常不愿意或难以督促采伐者进行这种投资。即使在这些问题能够解决的地方,保护的倡议仍需仔细地考虑天然林管理是否可能比其它方法导致更少的损害。这个问题的答案在于在缺乏林业计划的情况下会有什么样的人类干扰发生:是少还是没有,是不加控制的采伐还是农垦毁林,只有在后面情况下利用天然林管理无疑才会体现出环境的改善。最后必须对林业是否是达到自然保护目标的一种费用低廉的方式做出评估。在分析了上述因素后我们作出了一些特定的环境中天然林管理是一个有希望的保护对策的结论。

关键词：热带森林保护天然林管理管理

Speed and surface steepness affect internal tibial loading during running

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Journal of Sport and Health Science 2024年第1期13卷 118-124页

作者： Hannah rice Markus Kurz Patrick Mai Leon Robertz Kevin Bill Timothy R.Derrick Steffen Willwacher Department of Physical Performance Norwegian School of Sport SciencesOslo 0806Norway Sports Tech Research Centre Mid Sweden UniversityÖstersund SE-83125Sweden Department of Mechanical and Process engineering Offenburg University of Applied SciencesOffenburg 77652Germany Institute of Biomechanics and Orthopaedics German Sport University CologneCologne 50933Germany Department of Kinesiology Iowa State UniversityAmesIA 50011USA

Background:Internal tibial loading is influenced by modifiable factors with implications for the risk of stress *** encounter varied surface steepness(gradients)when running outdoors and may adapt their speed according to the *** study aimed to quantify tibial bending moments and stress at the anterior and posterior peripheries when running at different speeds on surfaces of different ***:Twenty recreational runners ran on a treadmill at 3 different speeds(2.5 m/s,3.0 m/s,and 3.5 m/s)and gradients(level:0%;uphill:+5%,+10%,and+15%;downhill:-5%,-10%,and-15%).Force and marker data were collected synchronously *** moments were estimated at the distal third centroid of the tibia about the medial-lateral axis by ensuring static equilibrium at each 1%of *** was derived from bending moments at the anterior and posterior peripheries by modeling the tibia as a hollow ***-way repeated-measures analysis of variance were conducted using both functional and discrete statistical ***:There were significant main effects for running speed and gradient on peak bending moments and peak anterior and posterior *** running speeds resulted in greater tibial *** uphill at+10%and+15%resulted in greater tibial loading than level *** downhill at-10%and-15%resulted in reduced tibial loading compared to level *** was no difference between+5%or-5%and level ***:Running at faster speeds and uphill on gradients≥+10%increased internal tibial loading,whereas slower running and downhill running on gradients≥-10%reduced internal *** running speed according to the gradient could be a protective mechanism,providing runners with a strategy to minimize the risk of tibial stress injuries.

关键词： Bending moments Gradient Musculoskeletal modeling Overuse injury Tibial stress Training factors

Sustainable land management in Mali

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Geography and Sustainability 2024年第3期5卷 382-391页

作者： Karim Nchare Marcel Vitouley richard Mbih Vanderbilt University USA African School of economics Benin Pennsylvania State University USA

This study uses logistic and Poisson regression models to examine the factors influencing the adoption of sustain-able land management(SLM)practices in Mali using two rounds of the nationally representative survey enquête Agricole de Conjoncture Intégrée aux Conditions de Vie des Mé*** SLMs considered include the applica-tion of organic fertilizers,the application of inorganic fertilizers,the use of improved seeds,and the practice of *** average the application of organic fertilizers(39.2%),and inorganic fertilizers(28.7%)are the most frequent SLM practices among Malian farmers,and between 2014 and 2017,we observe a decline in the practice of *** regression results show that farmers’adoption of different SLMs is significantly associated with biophysical factors(average temperature,climate type,plot size,plot shape,and location),de-mographic factors(age,gender,education,household size),and socioeconomic factors(number of cultivated plots,livelihood diversification,type of crop grown,market access,credit access,economic shocks,and social capital).Our findings suggest that policymakers and agricultural development agencies in Mali need to adopt a multidimensional policy framework to unlock the untapped potential of SLM practices in promoting sustainable agriculture and food security.

关键词： Sustainable land management Africa Logistic regression models Poisson regression model

Nearest Neighbor Sampling of Point Sets Using Rays

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Communications on Applied Mathematics and Computation 2024年第2期6卷 1131-1174页

作者： Liangchen Liu Louis Ly Colin B.Macdonald richard Tsai Department of Mathematics The University of Texas at Austin2515 SpeedwayAustinTX 78712USA Oden Institute for Computational engineering and Sciences The University of Texas at Austin201 E24th StAustinTX 78712USA Department of Mathematics University of British Columbia1984 Mathematics RdVancouverBCV6T1Z2Canada

We propose a new framework for the sampling,compression,and analysis of distributions of point sets and other geometric objects embedded in euclidean *** approach involves constructing a tensor called the RaySense sketch,which captures nearest neighbors from the underlying geometry of points along a set of *** explore various operations that can be performed on the RaySense sketch,leading to different properties and potential *** information about the data set can be extracted from the sketch,independent of the ray *** integrals on point sets can be efficiently computed using the *** also present several examples illustrating applications of the proposed strategy in practical scenarios.

关键词： Point clouds Sampling Classification Registration Deep learning Voronoi cell analysis

Simplified seismic scenario analysis of existing masonry buildings accounting for local site effects

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Frontiers of Structural and Civil engineering 2024年第2期18卷 309-318页

作者： Ayşe e.ÖZSOYÖZBAY Işıl SANRI KARAPINAR Zehra N.KUTLU İsmail e.KILIÇ Department of Civil engineering Maltepe UniversityIstanbul 34857Turkey School of engineering and Construction Oryx Universal CollegeDoha 12253Qatar

This study discusses the effects of local sites and hazard amplification on the seismic vulnerability assessment of existing masonry *** this context,a rapid seismic evaluation procedure was implemented on an old masonry building stock in the historical center Galata,located inİstanbul,to determine the seismic risk priority of the built *** scenarios were generated for all soil classes,different moment magnitudes,and source-to-site distances to obtain more accurate results for the seismic vulnerability assessment of the studied building ***,damage distributions estimated under nine different scenarios with/without site effects were compared and illustrated in maps to discuss changes in vulnerability owing to amplification *** this study,by re-examining the rapid seismic evaluation procedure by including geo-hazard-based assessment,the importance of site effects on the vulnerability and risk assessment of built heritage was *** proposed framework integrating field data and local site effects is believed to advance the current applications for vulnerability assessment of masonry buildings and provide an improvement in the application of rapid seismic assessment procedures with more reliable results.

关键词： masonry buildings seismic vulnerability assessment cultural heritage local site effect

Wildfire severity alters soil microbial exoenzyme production and fungal abundances in the southern Appalachian Mountains

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Pedosphere 2024年第5期34卷 865-878页

作者： Megan L.SCHILL richard BAIRD Shawn P.BROWN Allison M.VeACH Department of Integrative Biology University of Texas at San Antonio Biochemistry Molecular Biology Entomology and Plant Pathology Department Mississippi State University Department of Biological Sciences The University of Memphis

Climate change has increased drought frequency and duration that are exacerbated by increased temperatures globally. This effect has, and will continue,to increase fire occurrence across many regions of North America. In the southern Appalachian Mountains, wildfires with high burn severity occurred in 2016due to increased drought and human activity. To investigate the effects of burn severity on soil physicochemical properties, microbial extracellular enzyme production, and microbial abundances in a temperate region, surface soils (0–15 cm) were collected from two sites (the Great Smoky Mountains National Park in Tennessee and the Nantahala National Forest in North Carolina, USA) spanning lightly, moderately, and severely burned areas, accompanied by adjacent unburned locations that act as controls. The soil samples were collected at three time points between 2017 and 2019 (i.e., 0.5, 1, and 2.5 years post-fire)among burn severity plots. Total hydrolytic enzyme production varied over time, with severe burn plots having significantly lower enzyme production at 2.5years post-fire. Individual enzymes varied among burn severities and across time post-fire. Light burn plots showed greater carbon-specific (β-glucosidase and β-xylosidase) and phosphorus-specific (acid phosphatase) enzyme activities at 0.5 years post-fire, but this effect was transient. At 2.5 years post-fire, theβ-xylosidase and acid phosphatase activities were lower in severe or moderate burn plots relative to the controls. In contrast, the activity of nitrogen-specific enzyme leucyl aminopeptidase was the lowest in severe burn plots at 0.5 years post-fire, but was the lowest in light burn plots at 2.5 years post-fire. The fungi:bacteria ratio declined with burn severity, indicating that fungi are sensitive or less resilient to high burn severity during recovery. These results suggest that wildfires alter trajectories for soil microbial structure and function within a 2.5-year timeframe, which potentially

关键词： 16S carbon ITS nitrogen phosphorous

CLASSIFICATIONS OF DUPIN HYPeRSURFACeS IN LIe SPHeRe GeOMeTRY

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Acta Mathematica Scientia 2024年第1期44卷 1-36页

作者： Thomas e.CeCIL Department of Mathematics and Computer Science College of the Holy CrossWorcesterMA01610USA

This is a survey of local and global classification results concerning Dupin hypersurfaces in S^(n)(or R^(n))that have been obtained in the context of Lie sphere *** emphasis is on results that relate Dupin hypersurfaces to isoparametric hypersurfaces in *** with these classification results,many important concepts from Lie sphere geometry,such as curvature spheres,Lie curvatures,and Legendre lifts of submanifolds of S^(n)(or R^(n)),are described in *** paper also contains several important constructions of Dupin hypersurfaces with certain special properties.

关键词： Dupin hypersurfaces isoparametric hypersurfaces Lie sphere geometry Lie sphere transformations Lie curvatures

Investigating the impact of the universal function of the nuclear proximity potential in heavy-ion fusion cross sections

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Communications in Theoretical Physics 2024年第5期76卷 86-93页

作者： R Gharaei e Sarvari Department of Physics Sciences FacultyHakim Sabzevari UniversityPO Box 397SabzevarIran Department of Physics Faculty of ScienceFerdowsi University of MashhadPO Box 91775-1436MashhadIran Science Faculty Department of PhysicsTarbiat Modares UniversityTehranIran

The fusion barriers and cross sections of 15 colliding systems with 320≤Z_(1)Z_(2)≤1512 are investigated in detail to understand the influence of the universal function of proximity potential formalism in the heavy-ion fusion *** realize this goal,we select three versions of the phenomenological proximity potentials,including Prox.77,Zhang 2013,and Guo 2013,to calculate the nucleus-nucleus *** experimental fusion cross sections for the selected reactions are analyzed using the standard coupled-channel calculations,including couplings to the low-lying 2^(+)and 3^(-)states in the target and *** calculated results show that the universal functions of the Guo 2013 and Prox.77 models provide the lowest and highest fusion barriers,*** addition,it is found that the height of the fusion barriers is enhanced by increasing the mass number of the projectile from light to heavy *** highest sensitivity to the mass number of the projectile belongs to the results of Prox.77.A discussion is also presented on the influence of the universal function on the radial behavior of the interaction potential in the allowed region for overlapping *** results reveal that the best fit to the experimental data of the fusion cross sections for the reactions involving light and medium nuclei is obtained using the universal function of the Zhang 2013 *** the heavier systems,the results of the Guo 2013 model at sub-barrier energies provide a good description of the available data.

关键词： fusion reactions proximity-type potentials universal function coupled-channel calculations

Are hydrides under high-pressure-high-temperature superconductors?

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National Science Review 2024年第7期11卷 9-12页

作者： J.e.Hirsch Department of Physics University of California

Contrary to the current consensus, I argue that the existing evidence for high-temperature superconductivity in hydrides under high pressure is not compelling. I suggest that the focus of the field should urgently shift to establish unequivocally experimentally whether or not superconductivity in pressurized hydrides exists, instead of continuing to search for new materials that might show elusive signals of unproven superconductivity at ever higher temperatures. The implications of a negative finding for the theoretical understanding of superconductivity are discussed.

关键词： Hydrides