223 research outputs found
Hydrothermal conditions modulate the impact of climate extremes on vegetation growth in the Northern Hemisphere
No full text<p><strong><span>Aim</span></strong></p>
<p>Climate extremes are becoming more frequent under global warming, with substantial repercussions for vegetation growth. The degree to which climate extremes increase the risk of high-impact events on vegetation growth is of high concern.</p>
<p><strong>Location</strong></p>
<p>Northern Hemisphere (north of 30° N)<span>.</span></p>
<p><strong>Time Period</strong></p>
<p><span>F</span>rom 2001 to 2022<span>.</span></p>
<p><strong>Major Taxa Studied</strong></p>
<p><span>P</span><span>l</span><span>ants</span><span>.</span></p>
<p><strong>Methods</strong></p>
<p><span>W</span>e utilized solar-induced chlorophyll fluorescence (SIF) and the normalized difference vegetation index (NDVI) as proxies for vegetation growth and performed event coincidence and sensitivity analyses to attribute satellite-derived vegetation growth extremes to diverse climate extremes (extreme heat, cold, wet, and drought) in the Northern Hemisphere.</p>
<p><strong>Results</strong></p>
<p>Our results showed that extreme heat and cold were the main climatic extremes that induced positive and negative vegetation growth extremes north of 30° N, respectively, mainly in cold and humid ecosystems (boreal and temperate forests). Water-related extreme events accounted for less than one-third of vegetation extremes. The contribution of drought to positive vegetation growth extreme events (approximately 17%), mainly in cold and humid ecosystems, was even slightly higher than that of extreme wet (approximately 12%), which predominantly impacted relatively warm and arid ecosystems (croplands and temperate grasslands). We further identified potential climatic thresholds that could induce a reversal of vegetation growth responses to climate extremes and showed that the past <span>two</span> decades of warming and precipitation changes did not induce a shift in the main climatic drivers of vegetation extremes across northern ecosystems.</p>
<p><strong>Main Conclusions</strong></p>
<p>Our results emphasize the crucial role of background hydrothermal conditions in the attribution of vegetation growth extremes to diverse climate extremes across northern ecosystems and have substantial implications for predicting how Northern Hemisphere vegetation will respond to increasing climate extremes in the future.</p>
Hydrodeoxygenation of Biomass-derived Polyols into High Value-added Molecules over Bifunctional Heterogeneous Catalysts
Get PDFTohoku University博士（工学）博士学位論文 (Thesis(doctor))doctoral thesi
Hydrodeoxygenation of Biomass-derived Polyols into High Value-added Molecules over Bifunctional Heterogeneous Catalysts
No full textFast interfacial electrocatalytic desolvation enabling low-temperature and long-cycle-life aqueous Zn batteries
Get PDFLow-temperature zinc batteries (LT-ZIBs) based on aqueous electrolytes show great promise for practical applications owing to their natural resource abundance and low cost. However, they suffer from sluggish kinetics with elevated energy barriers due to the dissociation of bulky Zn(H2O)(6)(2+) solvation structure and free Zn2+ diffusion, resulting in unsatisfactory lifespan and performance. Herein, dissimilar to solvation shell tuning or layer spacing enlargement engineering, delocalized electrons in cathode through constructing intrinsic defect engineering is proposed to achieve a rapid electrocatalytic desolvation to obtain free Zn2+ for insertion/extraction. As revealed by density functional theory calculations and interfacial spectroscopic characterizations, the intrinsic delocalized electron distribution propels the Zn(H2O)(6)(2+) dissociation, forming a reversible interphase and facilitating Zn2+ diffusion across the electrolyte/cathode interface. The as-fabricated oxygen defect-rich V2O5 on hierarchical porous carbon (ODVO@HPC) electrode exhibits high capacity robustness from 25 to -20 degrees C. Operating at -20 degrees C, the ODVO@HPC delivers 191 mAh g(-1) at 50 A g(-1) and lasts for 50 000 cycles at 10 A g(-1), significantly enhancing the power density and lifespan under low-temperature environments in comparison to previous reports. Even with areal mass loading of similar to 13 mg cm(-2), both coin cells and pouch batteries maintain excellent stability and areal capacities, realizing practical high-performance LT-ZIBs
The impact of technology on foreign language anxiety: A systematic review of empirical studies from 2004 to 2024
No full textAbstract The advent of technology has significantly transformed various aspects of human activity and revolutionized language learning experiences. However, this shift from traditional learning models also introduces psychological pressure on learners, with anxiety being the most prominent emotional factor affecting language acquisition. To address this issue, this study conducts a systematic literature review, analyzing 99 empirical articles from EBSCO (APA PsycInfo & ERIC), Ei Compendex, Scopus, and Web of Science to explore how technology influences language learning anxiety and to propose strategies for minimizing anxiety in technology-assisted learning environments. The key findings include the following: (1) Mixed methods dominate the research landscape, with a strong focus on higher education. Speaking is the most extensively studied language skill, while research on artificial intelligence is growing rapidly. Only a small proportion of studies focus exclusively on anxiety or employ theoretical frameworks. (2) This study reveals that technology alleviates foreign language anxiety through psychological safety and personalized feedback while exacerbating it via cognitive overload and diminished human interaction, with these mechanisms being further analyzed through grounded theory. (3) Future research should develop theoretical frameworks that integrate the affective and cognitive dimensions of technology-mediated foreign language anxiety, investigate virtual reality and augmented reality applications beyond higher education contexts, and employ multimodal assessments that combine physiological measures with traditional self-reports
An empirical examination of the contents and evolution of the composing factors of logistics enterprise competitiveness: a perspective from China
Get PDFManagers and researchers are increasingly interested in the factor that logistics enterprise competitiveness(LEC) has significant effects on the development of Chinese logistics enterprises, especially in view of theenterprise life cycle. This paper investigates the contents and evolution of the composing factors of LEC inChina by a survey.With Statistical Product and Service Solutions (SPSS 15.0) software, the factor analysismethod is used to determine the effects of each factor on LEC. Furthermore, the comparative analysismethod is applied to compare the composing factors of LEC in different types of logistics enterprises andat different enterprise life cycle stages. The results show that factors of LEC according to their descendingimportance level are corporate capabilities, corporate resources, and dynamic mechanism. Three kindsof corporate capabilities (financial management capability, logistics risk control capability, and humanresource management capability) and two kinds of corporate resources (corporate human resources andcorporate culture) have the greatest influence on the development of LEC, but in reality have poor practicalperformance, and hence deserve more consideration from the enterprises.National Natural Science Foundation of ChinaHumanity and Social ScienceYouth Foundation of Ministry of Education of ChinaChina State Scholarship FundChina State Scholarship Fun
The role of control power allocation in service supply chains: Model analysis and empirical examination
No full textIn complex and competitive business environment, there have been many examples of supply chain members fighting for power. Therefore, researchers have begun focusing on the impact of control power allocation on the supply chain. This paper examines the allocation of power in different service supply chain relationships, analyzing the impact of service level on optimal control power allocation and comparing the differences between the optimal power distribution in service supply chains and that of manufacturing supply chains. We adopt a mathematical model building method to discuss this issue, verifying the theoretical perspectives through empirical studies of China's largest state-owned logistics company, the China Railway Company, and the private ownership enterprise, Tianjin SND Logistics Company. We also develop a conceptual model of the influence of control power on the performance of service supply chains, based on the modeling and case analysis. The conceptual model shows several results: the control power allocation determines the dominant structure of the supply chain; the service provider's wholesale pricing strategy and the service integrator's sales price strategy present different outcomes under various dominant structures of the supply chain, which will greatly affect the performance of the corresponding supply chain; and the relationship between the supply chain dominant structure and the price can be adjusted by the service level
Attraction of Sitophilus oryzae (L.) (Coleoptera: Curculionidae) to the semiochemical volatiles of stored rice materials
Get PDFIn order to explore the influence of stored cereal volatiles on the behavior of Sitophilus oryzae, the olfactory responses of adult rice weevils to the volatiles of different rice cultivars [Red brown rice (RBR), Daohuaxiangmi (DHXM), Baishuigongmi (BSGM), Yashuixinmi (YSXM), and white glutinous rice (WGR)] were studied using electroantennography (EAG) and behavioural bioassays in different types of olfactometers. S. oryzae showed significantly different preferences for these rice cultivars, in the order RBR > DHXM = YSXM ≥ BSGM > WGR. Furthermore, 26 components were identified in the volatile profile of RBR. Nonanal (29.37%), hexanal (16.08%), and 1-octen-3-ol (8.83%) were the most abundant compounds. EAG recordings showed that the antennae of S. oryzae were able to perceive these three compounds in a dose-dependent manner. The compounds elicited significant EAG responses at various concentrations, with the strongest responses at 100 μg μL−1. S. oryzae had a significant positive behavioural response to nonanal, hexanal, and 1-octen-3-ol at various concentrations, with the most attractive being 50, 100, and 100 μg μL−1, respectively. The olfactory preferences of S. oryzae, based on a comparison of these compounds at their optimal concentrations, were nonanal > 1-octen-3-ol = hexanal. These results indi- cated that the volatiles of the preferred rice cultivar (RBR) were perceived by the peripheral olfactory system of S. oryzae adults and individually elicited positive chemotaxis. These findings offer new insights into the mechanism of host prefer- ences of stored-grain pests. Nonanal showed the greatest potential for use as a novel monitoring and control tool against this storage-beetle pest
Selective hydrogenation of furfural over Pt based and Pd based bimetallic catalysts supported on modified multiwalled carbon nanotubes (MWNT)
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