Distribution of Panama’s narrow-range trees:are there hot-spots?

Background:Tree species with narrow ranges are a conservation concern because heightened extinction risk accompanies their small populations.Assessing risks for these species is challenging,however,especially in tropical flora where their sparse populations seldom appear in traditional plots and inventories.Here,we utilize instead large scale databases that combine tree records from many sources to test whether the narrow-range tree species of Panama are concentrated at certain elevations or in certain provinces.Past investigations have suggested that the Choco region of eastern Panama and the high mountains of western Panama may be potential hotspots of narrow-range tree species.Methods:All individual records were collected from public databases,and the range size of each tree species found in Panama was estimated as a polygon enclosing all its locations.Species with ranges<20,000 km^(2) were defined as narrow endemics.We divided Panama into geographic regions and elevation zones and counted the number of individual records and the species richness in each,separating narrow-range species from all other species.Results:The proportion of narrow endemics peaked at elevations above 2000 m,reaching 17.2% of the species recorded.At elevation<1500 m across the country,the proportion was 6-11%,except in the dry Pacific region,where it was 1.5%.Wet forests of the Caribbean coast had 8.4% narrow-range species,slightly higher than other regions.The total number of narrow endemics,however,peaked at mid-elevation,not high elevation,because total species richness was highest at mid-elevation.Conclusions:High elevation forests of west Panama had higher proportions of narrow endemic trees than low-elevation regions,supporting their hot-spot status,while dry lowland forests had the lowest proportion.This supports the notion that montane forests of Central America should be a conservation focus.However,given generally higher diversity at low-to mid-elevation,lowlands are also important habitats for narrow-range tree species,though conservation efforts here may not protect narrow-range tree species as efficiently.

Regional Variability of Climate Change Hot-Spots in East Asia

The regional climate change index （RCCI） is employed to investigate hot-spots under 21st century global warming over East Asia. The RCCI is calculated on a 1-degree resolution grid from the ensemble of CMIP3 simulations for the B1, AIB, and A2 IPCC emission scenarios. The RCCI over East Asia exhibits marked sub-regional variability. Five sub-regional hot-spots are identified over the area of investigation： three in the northern regions （Northeast China, Mongolia, and Northwest China）, one in eastern China, and one over the Tibetan Plateau. Contributions from different factors to the RCCI are discussed for the sub-regions. Analysis of the temporal evolution of the hot-spots throughout the 21st century shows different speeds of response time to global warming for the different sub-regions. Hot-spots firstly emerge in Northwest China and Mongolia. The Northeast China hot-spot becomes evident by the mid of the 21st century and it is the most prominent by the end of the century. While hot-spots are generally evident in all the 5 sub-regions for the A1B and A2 scenarios, only the Tibetan Plateau and Northwest China hot-spots emerge in the B1 scenario, which has the lowest greenhouse gas （GHG） concentrations. Our analysis indicates that subregional hot-spots show a rather complex spatial and temporal dependency on the GHG concentration and on the different factors contributing to the RCCI.

A preliminary experimental validation of superposition strategy in thermal management of integrated circuit with multiple hot-spots

Thermal management is a key issue in the integrated circuit(IC)design.In this paper,the superposition strategy was experimentally validated using a modeling IC device,which was fabricated by laboratory-level microfabrication technique.Metal thin film resistors on the top of dielectric layer were used to analogize the multiple hot-spots in the modeling IC device.The measured temperature rise with multiple hot-spots agrees well with the predictions given by the superposition calculations.With the help of the superposition strategy,thermal management of IC device can be significantly simplified by decomposing the system into sub-systems and optimizing each part individually.The influence coefficients in the superposition strategy extracted from the experimental measurement offer the IC designers a useful engineering tool to facility the thermal optimization and evaluate the thermal performance of IC devices.

Shape Analysis of Agricultural Parcels for Land Consolidation Priorities in Tekirdag Province,Turkey

Shape irregularity,a sub-factor of parcel fragmentation is a problem that hinders sustainable agriculture and is solved using land consolidation projects.Determination of the parcel shape degree contributes significantly to spatial prioritization where there is also a high probability of achieving positive effects of consolidation projects.This study aims to determine the shape degree of the agricultural parcels both at singular and rural county scales in Tekirdag Province,Turkey in 2020 by combining the parcel shape index(PSI) with the minimum bounding geometry index(MBG) to improve parcel scores.Hot-spot zones of the highly irregular and near optimum parcels were also determined using Getis-Ord G_(i)^(*) statistic.The parcel degrees were classified into four categories,namely highly irregular,irregular,regular and near optimum.The obtained unweighted scores of the parameters exhibit deviations from the expected values.After weighting by pairwise comparison,the values approached ideal scores.Among 346 740 parcels,53% were highly irregular and irregular and 47% were regular and near optimum shapes after weighting whereas these were 70% and 30%,respectively before weighting.The average parcel degree of 63 rural counties was regular while the average parcel degree of the remaining 264 rural counties was irregular.The combined use of PSI and MBG index improved the correctness of the parcel shape score.It could be suggested to use as a tool in land consolidation prioritization.

Study of the asymmetry of hot-spot self-emission imaging of inertial confinement fusion implosion driven by high-power laser facilities

Implosion asymmetry is a crucial problem quenching ignition in the field of inertial confinement fusion.A forward-calculation method based on 1D and 2D hydrodynamic simulations has been developed to generate and study the x-ray images of hot-spot self-emission,indicating asymmetry integrated over the entire drive pulse.It is shown that the x-ray imaging photon energy should be higher to avoid the influence of the remaining shell.The contour level(percentage of the maximum emission intensity)and spatial resolution should be as low as possible,optimally less than 20%and 3μm,for characterization of higher-mode signatures such as Ps-P12 by x-ray self-emission images.On the contrary,signatures of lower-mode such as P2 remain clear at all contour levels and spatial resolutions.These key results can help determine the optimal diagnostics,laser,and target parameters for implosion experiments.Recent typical hot-spot asymmetry measurements and applications on the Shenguang 100 kJ class laser facility are also reported.

Discussion of a Failure Hot-Spot Endurance Testing Case for CIGS Thin-Film Photovoltaic Module

This paper describes the use of steady-state solar simulator for CIGS thin-film photovoltaic module hot-spot endurance test. In the study, not only are test procedures of hot-spot endurance test in IEC 61646 discussed, but also how to evaluate the performance of steady-state solar simulator by IEC 60904-9 is presented. Three CIGS thin-film PV modules with the same types are used for hot-spot endurance test in case study. It is found that some of the cell damages and visual defects on tested PV modules are clearly observed.

Analysis of structural hot-spot stress in orthotropic plates

On the basis of the actual steel deck structure of Taizhou Bridge, this paper carries out hot-spot stress analysis on some key spots by using the finite element model which simulates local structure of orthotropic steel bridge decks. A finite element model is established for local structure of orthotropic steel bridge decks, and in the analysis of linear elasticity of the structure, face load is employed to simulate the loads from vehicle wheels. Analysis results show that main stresses are relatively heavy at the joints between diaphragm plates, top plates and U-shaped ribs and the joints between diaphragm plates and U-shaped ribs. These joints shall be regarded as key points for hot-spot stress analysis. Different mesh densities are adopted in the finite element model and the main stresses at different hot spots are contrasted and linear extrapolation is carried out using extrapolation formulae. Results show that different mesh densities have different influences on the hot-spot stresses at the welded seams of U-shaped ribs. These influences shall be considered in calculation and analysis.

The Lower Cretaceous Giant Dyke Swarms in the Arctic and Its Significance for linking of Siberia-Iceland Hot-Spot Track

Siberia-Iceland hot-spot track is the one of hot-spot track preserved on continent.Although this hot-spot track has clear plume"heads"-Siberia large igneous province,owing to thick continental lithosphere,its continuing

Voltage-Based Hot-Spot Detection Method for Defective Cell in Photovoltaic Module Using Projector

This paper proposes a voltage-based hot-spot detection method for defective cells in PV module using projector. The presence of internal crystal defects is one of the main causes of hot-spot phenomenon in PV modules. Authors previously investigated the physical characteristics of hot-spot phenomenon referring to internal crystal defect. Based on it, a hot-spot detection method named as current-based SRC （self reverse current） detection method is developed. However, it becomes extraordinarily complicated to determine the defective cells under low illumination. In order to avoid this disadvantage, authors improve the SRC detection method by applying voltage. From the feasibility experiment results, it is confirmed that by calculating cell HSI （hotspots index） with voltage, the PV modules with defective cells can be prospectively excluded even under low illumination.

Hot-Spot Detection System with Correction of Operating Point for PV Generation System

Currently, the production and the number of installations of PV （photovoltaic） modules have been increasing rapidly because of a feed-in tariff in Japan. Accordingly, the number of failures has also increased. Many failures are a result of the Hot-Spot phenomenon in which defective cell becomes hot when shadow occurs on the cell, On the other hand, if shadow occurs on normal cell, there are cases that P＆O method that is MPPT （maximum power point tracking） control method incorporated in conventional PV system cannot track maximum power point and generated power decreases. The correspondence is required rapidly if these trouble occur. However, conventional PV system monitors generated power, correspondence is impossible by monitoring generated power. Previously, the authors developed real time Hot-Spot detection system that incorporates into PCS （power conditioning system）. Thus, the authors developed plug-in type Hot-Spot monitoring system that includes ＂PV peak shift method＂ and confirmed effectiveness of the system in this time. ＂PV peak shift method＂ loads ＂Scan method＂ that is MPPT control method and measures I-V （current-voltage） characteristic by changing voltage of module from open to short by ＂Scan method＂ on a regular basis. The developed Hot-Spot monitoring system uses slope of I-V characteristic of PV module. Inserting developed system into already installed PV system, Hot-Spot can be easily monitored in real time and PV system can be operated at maximum power point.

中太平洋海山群漂移史及其来源

中太平洋海山群的海山呈簇状排列且近EW向展布于太平洋海山密集区,其四周分布着一系列NW走向的线性列岛及规模巨大的水下海山链.它位于明显属于海山链构造的夏威夷群岛和马绍尔群岛之间,处于莱恩群岛的北西向延伸方向上,与热点作用的板内火山作用关系密切.结合前人对中太平洋海山群形成和漂移的认识,从板决运动和几何学角度出发,采用Backtracking和Hot-spotting海山追踪方法对该区海山进行了追踪,发现该区海山的热点源主要位于现今法属玻利尼西亚群岛区(法属玻利尼西亚热点群),这与前人从古地磁和钻探资料出发得到的结果相接近.研究表明,中太平洋海山群是多热点成因的板内火山作用和板块构造运动的共同产物,它在130～90 Ma期间起源于法属玻利尼西亚热点群,曾随着太平洋板块发生过向南和向北的运动,既有水平方向的漂移又有垂直方向上的升降,在漂移和升降过程中还受到了当时大规模多期的热点活动和断裂活动的改造作用,经过一个漫长的过程后才到达今天的位置,最后形成了现今呈簇状分布的海山群.

麦哲伦海山链漂移史及可能的来源

麦哲伦海山链主要由十多座相对独立的平顶海山组成,呈北西向展布于太平洋海山密集区。结合前人对麦哲伦海山链形成和漂移的认识,从板块运动和几何学角度出发采用backtracking和hot-spotting海山追踪方法对该区海山的起源与形成进行了研究,结果表明,麦哲伦海山链是多热点成因的板内火山和板块构造运动共同作用的产物,最初于白垩纪期间由法属玻利尼西亚热点群西侧呈北北西向排列的热点活动产生,继而受到板块运动与区内近南北向和北北东向两组断裂及其热活化等的改造作用,最后形成了现今看到的平顶海山。

Non-equilibrium between ions and electrons inside hot spots from National Ignition Facility experiments

The non-equilibrium between ions and electrons in the hot spot can relax the ignition conditions in inertial confinement fusion[Fan et al.,Phys.Plasmas 23,010703(2016)],and obvious ion-electron non-equilibrium could be observed by our simulations of high-foot implosions when the ion-electron relaxation is enlarged by a factor of 2.On the other hand,in many shots of high-foot implosions on the National Ignition Facility,the observed X-ray enhancement factors due to ablator mixing into the hot spot are less than unity assuming electrons and ions have the same temperature[Meezan et al.,Phys.Plasmas 22,062703(2015)],which is not self-consistent because it can lead to negative ablator mixing into the hot spot.Actually,this non-consistency implies ion-electron non-equilibrium within the hot spot.From our study,we can infer that ion-electron non-equilibrium exists in high-foot implosions and the ion temperature could be~9%larger than the equilibrium temperature in some NIF shots.

Spatial and temporal variation of global LAI during 1981-2006

Earth is always changing. Knowledge about where changes happened is the first step for us to understand how these changes affect our lives. In this paper, we use a long-term leaf area index data （LAI） to identify where changes happened and where has experienced the strongest change around the globe during 1981-2006. Results show that, over the past 26 years, LAI has generally increased at a rate of 0.0013 per year around the globe. The strongest increasing trend is around 0.0032 per year in the middle and northern high latitudes （north of 30°N）. LAI has prominently increased in Europe, Siberia, Indian Peninsula, America and south Canada, South region of Sahara, southwest corner of Australia and Kgalagadi Basin; while noticeably decreased in Southeast Asia, southeastern China, central Africa, central and southern South America and arctic areas in North America.

Stress Concentration Factors at Saddle and Crown Positions on the Central Brace of Two-Planar Welded CHS DKT-connections

A set of parametric stress analyses was carried out for two-planar tubular DKT-joints under different axial loading conditions. The analysis results were used to present general remarks on the effects of the geometrical parameters on stress concentration factors （SCFs） at the inner saddle, outer saddle, and crown positions on the central brace. Based on results of finite element （FE） analysis and through nonlinear regression analysis, a new set of SCF parametric equations was established for fatigue design purposes. An assessment study of equations was conducted against the experimental data and original SCF database. The satisfaction of acceptance criteria proposed by the UK Department of Energy （UK DoE） was also checked. Results of parametric study showed that highly remarkable differences exist between the SCF values in a multi-planar DKT-joint and the corresponding SCFs in an equivalent uni-planar KT-joint having the same geometrical properties. It can be clearly concluded from this observation that using the equations proposed for uni-planar KT-connections to compute the SCFs in multi-planar DKT-joints will lead to either considerably under-predicting or over-predicting results. Hence, it is necessary to develop SCF formulae specially designed for multi-planar DKT-joints. Good results of equation assessment according to UK DoE acceptance criteria, high values of correlation coefficients, and the satisfactory agreement between the predictions of the proposed equations and the experimental data guarantee the accuracy of the equations. Therefore, the developed equations can be reliably used for fatigue design of offshore structures.

Selection Methodology of High-Cycle Fatigue Analysis Approach for Damage Estimation in Welded Structural Joints

The main purpose of this paper is to provide a summarized general guideline to aid decision making of choosing the type of fatigue analysis approach,best suited for modelling and evaluating high-cycle fatigue damage in welded structural joints.It describes how addition of stress concentration and stress direction information into fatigue assessment methodology affect simulated fatigue damage accumulation results and when it is beneficial or necessary to use a particular fatigue damage estimation approach.The focus is on stress-life curve based approaches,particularly when deciding between variants of nominal,hot-spot or multiaxial fatigue assessment approaches for evaluating fatigue damage within welded joint structures.Evaluation is illustrated through application of proposed methodology to choose and perform fatigue assessment for a non-conventional load-bearing tubular joint structure within a floating lemniscate crane upper arm,which has been observed of being prone to aggressive crack propagation within its welds.Damage within the structure is estimated using two non-optimal fatigue analysis approaches to verify applicability of proposed selection methodology.Results are then summarized through comparative assessment and findings are discussed based on what leads to result changes within each fatigue damage analysis approach.

Energy-Efcient Transmission Range Optimization Model for WSN-Based Internet of Thing

With the explosive advancements in wireless communications and digital electronics,some tiny devices,sensors,became a part of our daily life in numerous elds.Wireless sensor networks(WSNs)is composed of tiny sensor devices.WSNs have emerged as a key technology enabling the realization of the Internet of Things(IoT).In particular,the sensor-based revolution of WSN-based IoT has led to considerable technological growth in nearly all circles of our life such as smart cities,smart homes,smart healthcare,security applications,environmental monitoring,etc.However,the limitations of energy,communication range,and computational resources are bottlenecks to the widespread applications of this technology.In order to tackle these issues,in this paper,we propose an Energy-efcient Transmission Range Optimized Model for IoT(ETROMI),which can optimize the transmission range of the sensor nodes to curb the hot-spot problem occurring in multi-hop communication.In particular,we maximize the transmission range by employing linear programming to alleviate the sensor nodes’energy consumption and considerably enhance the network longevity compared to that achievable using state-of-the-art algorithms.Through extensive simulation results,we demonstrate the superiority of the proposed model.ETROMI is expected to be extensively used for various smart city,smart home,and smart healthcare applications in which the transmission range of the sensor nodes is a key concern.

A melt-cast Duan-Zhang-Kim mesoscopic reaction rate model and experiment for shock initiation of melt-cast explosives

A melt-cast Duan-Zhang-Kim(DZK)mesoscopic reaction rate model is developed for the shock initiation of melt-cast explosives based on the pore collapse hot-spot ignition mechanism.A series of shock initiation experiments was performed for the Comp B melt-cast explosive to estimate effects of the loading pressure and the particle size of granular explosive component,and the mesoscopic model is validated against the experimental data.Further numerical simulations indicate that the initial density and formula proportion greatly affect the hot-spot ignition of melt-cast explosives.

Computational Analysis for Residue-Specific CDK2-Inhibitor Bindings

Cyclin-dependent kinase 2 (CDK2) is a key macromolecule in cell cycle regulation. In cancer cells, CDK2 is often overexpressed and its inhibition is an effective therapy of many cancers including breast carcinomas, leukemia, and lymphomas. Quantitative characterization of the interactions between CDK2 and its inhibitors at atomic level may provide a deep understanding of protein-inhibitor interactions and clues for more effective drug discovery. In this study, we have used the computational alanine scanning approach in combination with an efficient interaction entropy method to study the microscopic mechanism of binding between CDK2 and its 13 inhibitors. The total binding free energy from the method shows a correlation of 0.76?0.83 with the experimental values. The free energy component reveals two binding mode in the 13 complexes, namely van der Waals dominant, and electrostatic dominant. Decomposition of the total energy to per-residue contribution allows us to identify five hydrophobic residues as hot spots during the binding. Residues that are responsible for determining the strength of the binding were also analyzed.

Metagenomic profiles of soil microbiota under two different cropping systems detected by STRs-based PCR

In this research, soil microbial structures under a wheat triennial monoculture and horse bean-wheat-horse bean succession were evidenced using a metagenomic approach. Polymorphism analysis of DNA extracted from soil samples collected at the end of the third year of the two crop successions, was performed by PCR, carried-out with six different primers designed on simple tandem repeats sequences. Readable profiles were obtained with M13 primer, from which no polymorphisms were detected, and with the primer (GACA)4, that gave distinctive patterns. Experimental findings suggest that metagenomic analysis performed by (GACA)4 primer may be an easy and suitable method to discriminate microbial diversity of different crop successions. (GACA)4 PCR-pattern indicate that soil microbiota changes are well correlated with crop succession.