In dry attachment systems of spiders and geckos, van der Waals forces mediate attraction between substrate and animal tarsus. In particular, the scopula of Evarcha arcuata spiders allows for reversible attachment and ...In dry attachment systems of spiders and geckos, van der Waals forces mediate attraction between substrate and animal tarsus. In particular, the scopula of Evarcha arcuata spiders allows for reversible attachment and easy detachment to a broad range of surfaces. Hence, reproducing the scopula's roughness compatibility while maintaining anti-bunching features and dirt particle repellence behavior is a central task for a biomimetic transfer to an engineered model. In the present work we model the scopula of E. arcuata from a mechano-elastic point of view analyzing the influence of its hierarchical structure on the attachment behavior. By considering biological data of the gecko and spider, and the simulation results, the adhesive capabilities of the two animals are compared and important confirmations and new directives in order to reproduce the overall structure are found. Moreover, a possible suggestion of how the spider detaches in an easy and fast manner is proposed and supported by the results.展开更多
This paper presents and compares four mathematical models with unique spatial effects for a prey-predator system, with Tetranychus urticae as prey and Phytoseiulus persimilis as predator. Tetranychus urticae, also kno...This paper presents and compares four mathematical models with unique spatial effects for a prey-predator system, with Tetranychus urticae as prey and Phytoseiulus persimilis as predator. Tetranychus urticae, also known as two-spotted spider mite, is a harmful plant-feeding pest that causes damage to over 300 species of plants. Its predator, Phytoseiulus persimilis, a mite in the Family Phytoseiidae, effectively controls spider mite populations. In this study, we compared four mathematical models using a numerical simulation. These models include two known models: self-diffusion, and cross-diffusion, and two new models: chemotaxis effect model, and integro diffusion model, all with a Beddington-De Angelis functional response. The modeling results were validated by fitting experimental data. Results demonstrate that interaction scheme plays an important role in the prey-predator system and that the cross-diffusion model fits the real system best. The main contribution of this paper is in the two new models developed, as well as the validation of all the models using experimental data.展开更多
背景作为脑卒中患者康复效果的重要评定指标之一,社会参与逐渐受到关注,了解脑卒中患者对社会参与的认知和经历有利于帮助脑卒中患者快速康复、回归家庭并重新融入社会,但单一的质性研究结果可能不具有概括性和代表性。目的通过Meta整...背景作为脑卒中患者康复效果的重要评定指标之一,社会参与逐渐受到关注,了解脑卒中患者对社会参与的认知和经历有利于帮助脑卒中患者快速康复、回归家庭并重新融入社会,但单一的质性研究结果可能不具有概括性和代表性。目的通过Meta整合方法系统梳理关于脑卒中患者对社会参与认知和经历的质性研究,为进一步提高脑卒中患者康复效果提供参考。方法使用计算机检索PubMed、Web of Science、Cochrane Library、Embase、心理学文摘(PsycINFO)、护理和联合卫生文献累积索引(CINAHL)、澳大利亚乔安娜布里格斯研究所(JBI)循证卫生保健数据库、中国知网、万方数据知识服务平台、维普网、中国生物医学文献数据库,筛选其自建库至2022年11月以来收录的关于脑卒中患者对社会参与认知和经历的质性研究。采用汇集性Meta整合法对研究主题、隐含意义、分类等研究结果进行Meta整合。结果纳入Meta整合的14篇文献共涉及183例脑卒中患者,通过Meta整合共得出26个研究结果,其中相近结果可归纳为8个新类别,最终归纳出3个整合结果:(1)脑卒中患者对社会参与的认知和经历;(2)脑卒中患者多种社会参与受限且受较多因素影响;(3)多方支持对脑卒中患者社会参与至关重要。结论脑卒中患者对社会参与有新见解,须纠正和消除脑卒中患者对社会参与的自我认同紊乱及其限制因素,并重视脑卒中患者社会参与的多方支持。展开更多
The static modeling and dynamic simulation are essential and critical processes in petroleum exploration and development. In this study, lithofacies models for Wabiskaw Member in Athabasca, Canada are generated by mul...The static modeling and dynamic simulation are essential and critical processes in petroleum exploration and development. In this study, lithofacies models for Wabiskaw Member in Athabasca, Canada are generated by multipoint statistics(MPS) and then compared with the models built by sequential indicator simulation(SIS). Three training images(Tls) are selected from modern depositional environments;the Orinoco River Delta estuary, Cobequid bay-Salmon River estuary, and Danube River delta environment. In order to validate lithofacies models, average and variance of similarity in lithofacies are calculated through random and zonal blind-well tests.In random six-blind-well test, similarity average of MPS models is higher than that of SIS model. The Salmon MPS model closely resembles facies pattern of Wabiskaw Member in subsurface. Zonal blind-well tests show that successful lithofacies modeling for transitional depositional setting requires additional or proper zonation information on horizontal variation, vertical proportion, and secondary data.As Wabiskaw Member is frontier oilsands lease, it is impossible to evaluate the economics from production data or dynamic simulation. In this study, a dynamic steam assisted gravity drainage(SAGD)performance indicator(SPIDER) on the basis of reservoir characteristics is calculated to build 3 D reservoir model for the evaluation of the SAGD feasibility in Wabiskaw Member. SPIDER depends on reservoir properties, economic limit of steam-oil ratio, and bitumen price. Reservoir properties like porosity,permeability, and water saturation are measured from 13 cores and calculated from 201 well-logs. Three dimensional volumes of reservoir properties are constructed mostly based on relationships among properties. Finally, net present value(NPV) volume can be built by equation relating NPV and SPIDER. The economic area exceeding criterion of US$ 10,000 is identified, and the ranges of reservoir properties are estimated. NPV-volume-generation workflow from reservoir parameter to static model provides costand time-effective method to evaluate the oilsands SAGD project.展开更多
基金supported by the ARIADNA scheme (study ID 06/6201) of the European Space Agency
文摘In dry attachment systems of spiders and geckos, van der Waals forces mediate attraction between substrate and animal tarsus. In particular, the scopula of Evarcha arcuata spiders allows for reversible attachment and easy detachment to a broad range of surfaces. Hence, reproducing the scopula's roughness compatibility while maintaining anti-bunching features and dirt particle repellence behavior is a central task for a biomimetic transfer to an engineered model. In the present work we model the scopula of E. arcuata from a mechano-elastic point of view analyzing the influence of its hierarchical structure on the attachment behavior. By considering biological data of the gecko and spider, and the simulation results, the adhesive capabilities of the two animals are compared and important confirmations and new directives in order to reproduce the overall structure are found. Moreover, a possible suggestion of how the spider detaches in an easy and fast manner is proposed and supported by the results.
文摘This paper presents and compares four mathematical models with unique spatial effects for a prey-predator system, with Tetranychus urticae as prey and Phytoseiulus persimilis as predator. Tetranychus urticae, also known as two-spotted spider mite, is a harmful plant-feeding pest that causes damage to over 300 species of plants. Its predator, Phytoseiulus persimilis, a mite in the Family Phytoseiidae, effectively controls spider mite populations. In this study, we compared four mathematical models using a numerical simulation. These models include two known models: self-diffusion, and cross-diffusion, and two new models: chemotaxis effect model, and integro diffusion model, all with a Beddington-De Angelis functional response. The modeling results were validated by fitting experimental data. Results demonstrate that interaction scheme plays an important role in the prey-predator system and that the cross-diffusion model fits the real system best. The main contribution of this paper is in the two new models developed, as well as the validation of all the models using experimental data.
文摘背景作为脑卒中患者康复效果的重要评定指标之一,社会参与逐渐受到关注,了解脑卒中患者对社会参与的认知和经历有利于帮助脑卒中患者快速康复、回归家庭并重新融入社会,但单一的质性研究结果可能不具有概括性和代表性。目的通过Meta整合方法系统梳理关于脑卒中患者对社会参与认知和经历的质性研究,为进一步提高脑卒中患者康复效果提供参考。方法使用计算机检索PubMed、Web of Science、Cochrane Library、Embase、心理学文摘(PsycINFO)、护理和联合卫生文献累积索引(CINAHL)、澳大利亚乔安娜布里格斯研究所(JBI)循证卫生保健数据库、中国知网、万方数据知识服务平台、维普网、中国生物医学文献数据库,筛选其自建库至2022年11月以来收录的关于脑卒中患者对社会参与认知和经历的质性研究。采用汇集性Meta整合法对研究主题、隐含意义、分类等研究结果进行Meta整合。结果纳入Meta整合的14篇文献共涉及183例脑卒中患者,通过Meta整合共得出26个研究结果,其中相近结果可归纳为8个新类别,最终归纳出3个整合结果:(1)脑卒中患者对社会参与的认知和经历;(2)脑卒中患者多种社会参与受限且受较多因素影响;(3)多方支持对脑卒中患者社会参与至关重要。结论脑卒中患者对社会参与有新见解,须纠正和消除脑卒中患者对社会参与的自我认同紊乱及其限制因素,并重视脑卒中患者社会参与的多方支持。
基金supported by the Energy Efficiency and Resources Program of the Korea Institute of Energy Technology Evaluation andPlanning(KETEP,Grant No.20132510100060)the Basic Research Program of Korea Institute of Geoscience and Mineral Resources(KIGAM,GP2017-024)+2 种基金funded by the Ministry of ScienceICTFuture Planning of Korea
文摘The static modeling and dynamic simulation are essential and critical processes in petroleum exploration and development. In this study, lithofacies models for Wabiskaw Member in Athabasca, Canada are generated by multipoint statistics(MPS) and then compared with the models built by sequential indicator simulation(SIS). Three training images(Tls) are selected from modern depositional environments;the Orinoco River Delta estuary, Cobequid bay-Salmon River estuary, and Danube River delta environment. In order to validate lithofacies models, average and variance of similarity in lithofacies are calculated through random and zonal blind-well tests.In random six-blind-well test, similarity average of MPS models is higher than that of SIS model. The Salmon MPS model closely resembles facies pattern of Wabiskaw Member in subsurface. Zonal blind-well tests show that successful lithofacies modeling for transitional depositional setting requires additional or proper zonation information on horizontal variation, vertical proportion, and secondary data.As Wabiskaw Member is frontier oilsands lease, it is impossible to evaluate the economics from production data or dynamic simulation. In this study, a dynamic steam assisted gravity drainage(SAGD)performance indicator(SPIDER) on the basis of reservoir characteristics is calculated to build 3 D reservoir model for the evaluation of the SAGD feasibility in Wabiskaw Member. SPIDER depends on reservoir properties, economic limit of steam-oil ratio, and bitumen price. Reservoir properties like porosity,permeability, and water saturation are measured from 13 cores and calculated from 201 well-logs. Three dimensional volumes of reservoir properties are constructed mostly based on relationships among properties. Finally, net present value(NPV) volume can be built by equation relating NPV and SPIDER. The economic area exceeding criterion of US$ 10,000 is identified, and the ranges of reservoir properties are estimated. NPV-volume-generation workflow from reservoir parameter to static model provides costand time-effective method to evaluate the oilsands SAGD project.
