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Three-dimensional carbon microclusters organized by hollow carbon nanospheres for stable Li metal anodes:enabling high packing density and low tortuosity via self-assembly 被引量:1
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作者 Du Yeol Jo Jae Bong Lim +2 位作者 Jin Koo Kim Yun Chan Kang Seung-Keun Park 《Rare Metals》 2025年第1期95-109,共15页
Recently,hollow carbon nanospheres(HCSs)have garnered significant attention as potential Li metal hosts owing to their unique large voids and ease of fabrication.However,similar to other nanoscale hosts,their practica... Recently,hollow carbon nanospheres(HCSs)have garnered significant attention as potential Li metal hosts owing to their unique large voids and ease of fabrication.However,similar to other nanoscale hosts,their practical performance is limited by inhomogeneous agglomeration,increased binder requirements,and high tortuosity within the electrode.To overcome these problems and high tortuosity within the electrode,this study introduces a pomegranate-like carbon microcluster composed of primary HCSs(P-CMs)as a novel Li metal host.This unique nanostructure can be easily prepared using the spray-drying technique,enabling its mass production.Comprehensive analyses with various tools demonstrate that compared with HCS hosts,the P-CM host requires a smaller amount of binder to fabricate a sufficiently robust and even surface electrode.Furthermore,owing to reduced tortuosity,the well-designed P-CM electrode can provide continuous and shortened pathways for electron/ion transport,accelerating the Li-ion transfer kinetics and prohibiting preferential Li plating at the upper region of the electrode.Due to these characteristics,Li metal can be effectively encapsulated in the large inner voids of the primary HCSs constituting the P-CM,thereby enhancing the electrochemical performance of P-CM hosts in Li metal batteries.Specifically,the Coulombic efficiency of the P-CM host can be maintained at 97%over 100 cycles,with a high Li deposition areal capacity of 3 mAh·cm^(-2)and long cycle life(1000 h,1 mA·cm^(-2),and 1.0 mAh·cm^(-2)).Furthermore,a full cell incorporating a LiFePO4 cathode exhibits excellent cycle life. 展开更多
关键词 Li metal host Hollow carbon nanosphere Carbon microclusters SELF-ASSEMBLY tortuosity Spray drying
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Characterizing permeability-porosity relationships of porous rocks using a stress sensitivity model in consideration of elastic-structural deformation and tortuosity sensitivity
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作者 Ronghe Xu Liqin Wang +1 位作者 Xiaoli Zhao Yuze Mao 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第9期3437-3451,共15页
Clarifying the relationship between stress sensitivities of permeability and porosity is of great significance in guiding underground resource mining.More and more studies focus on how to construct stress sensitivity ... Clarifying the relationship between stress sensitivities of permeability and porosity is of great significance in guiding underground resource mining.More and more studies focus on how to construct stress sensitivity models to describe the relationship and obtain a comprehensive stress sensitivity of porous rock.However,the limitations of elastic deformation calculation and incompleteness of considered tortuosity sensitivity lead to the fact that the existing stress sensitivity models are still unsatisfactory in terms of accuracy and generalization.Therefore,a more accurate and generic stress sensitivity model considering elastic-structural deformation of capillary cross-section and tortuosity sensitivity is proposed in this paper.The elastic deformation is derived from the fractal scaling model and Hooke's law.Considering the effects of elastic-structural deformation on tortuosity sensitivity,an empirical formula is proposed,and the conditions for its applicability are clarified.The predictive performance of the proposed model for the permeability-porosity relationships is validated in several sets of publicly available experimental data.These experimental data are from different rocks under different pressure cycles.The mean and standard deviation of relative errors of predicted stress sensitivity with respect to experimental data are 2.63%and 1.91%.Compared with other models,the proposed model has higher accuracy and better predictive generalization performance.It is also found that the porosity sensitivity exponent a,which can describe permeability-porosity relationships,is 2 when only elastic deformation is considered.a decreases from 2 when structural deformation is also considered.In addition,a may be greater than 3 due to the increase in tortuosity sensitivity when tortuosity sensitivity is considered even if the rock is not fractured. 展开更多
关键词 Stress sensitivity model Permeability-porosity relationships Elastic-structural deformation tortuosity stress sensitivity
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Tortuosity factor for porous FeAl intermetallics fabricated by reactive synthesis 被引量:11
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作者 高海燕 贺跃辉 +2 位作者 ZOU Jin 徐南平 C.T.LIU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第9期2179-2183,共5页
The tortuosity factor is the most critical parameter for the pore characteristic of porous materials. The tortuosity factor for porous FeAl intermetallics was studied based on the Darcy law and Hagen-Poiseuille equati... The tortuosity factor is the most critical parameter for the pore characteristic of porous materials. The tortuosity factor for porous FeAl intermetallics was studied based on the Darcy law and Hagen-Poiseuille equation. Porous stainless steel with the same pore structure parameter as porous FeAl was fabricated by powder metallurgy method for comparison. The results show that the tortuosity factor of porous FeAl intermetallics is smaller than that of porous stainless steel when their pore structure parameters are the same. The average tortuosity factor is 2.26 for the porous FeAl material and 2.92 for the porous stainless steel, calculated by Hagen-Poiseuille equation. The reason of the different tortuosity factors for porous FeAl and porous stainless steel was also explored through studying the pore formation mechanisms of the two types of porous materials. 展开更多
关键词 FEAL INTERMETALLICS porous material tortuosity factor
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Tortuosity for streamlines in porous media 被引量:2
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作者 寇建龙 唐学明 +4 位作者 张海燕 陆杭军 吴锋民 许友生 董永胜 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第4期364-369,共6页
An analysis of tortuosity for streamlines in porous media is presented by coupling the circle and square models. It is assulued that some particles in porous media do not overlap and that fluid in porous media is inco... An analysis of tortuosity for streamlines in porous media is presented by coupling the circle and square models. It is assulued that some particles in porous media do not overlap and that fluid in porous media is incompressible. The relationship between tortuosity and porosity is attained with different configurations by using a statistical method. In addition, the tortuosity fractal dimension is expressed as a function of porosity. Those correlations do not include any empirical constant. The percolation threshold and tortuosity fractal dimension threshold of porous media are also presented as: φc = 0.32, DT,: = 1.07. The predicted correlations of the tortuosity and the porosity agree well with the existing experimental and simulated results. 展开更多
关键词 tortuosity tortuosity fractal dimension porous media
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Pore constitution and tortuosity factor of reactively synthesized porous TiAl intermetallic compound 被引量:4
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作者 Yao JIANG Yue-hui HE Hai-yan GAO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第3期726-733,共8页
The pore constitution and tortuosity factor of porous TiAl intermetallic were studied on the basis of the variation behavior of pore structure parameters and the discrete particle model. The pore formation mechanism o... The pore constitution and tortuosity factor of porous TiAl intermetallic were studied on the basis of the variation behavior of pore structure parameters and the discrete particle model. The pore formation mechanism of porous TiAl is mainly ascribed to three aspects: the clearance space in green compact, the diffusive pores in the reaction process and the phase transition pores, resulting in the open porosities of 5.6%, 42.9% and 1.3%, respectively. According to the Hagen-Poiseuille equation, the tortuosity factor of porous TiAl is determined in the range of 1.3-2.2. Based on the discrete particle model and the variation rule of the tortuosity factor, the tortuosity factor depends mainly on the parameters of fabrication constant, particle shape factor, clearance distance and powder particle size. The quantitative relationships among them have been established, which can be used as the basis for adjusting the pore structure of porous intermetallics. 展开更多
关键词 pore constitution tortuosity factor TiAl intermetallics porous material reactive synthesis
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A high-tortuosity holey graphene in-situ derived from cytomembrane/cytoderm boosts ultrastable potassium storage 被引量:1
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作者 Jun Xiao Xin Min +6 位作者 Yue Lin Qiyao Yu Wei Wang Xiaowen Wu Yangai Liu Zhaohui Huang Minghao Fang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2023年第8期69-78,共10页
The sluggish K^(+)kinetics and structural instability of the generally-used graphite and other carbon-based materials hinder the development of potassium-ion batteries(PIBs)for high-rate capability and long-term cycli... The sluggish K^(+)kinetics and structural instability of the generally-used graphite and other carbon-based materials hinder the development of potassium-ion batteries(PIBs)for high-rate capability and long-term cycling.Herein,inspired by the unique flake structure and chemical composition of cytomembrane and cytoderm,we design high-tortuosity holey graphene as a highly efficient anode for PIBs.The flake cytomembrane and cytoderm shrink into wrinkled morphology during drying and sintering and then convert into high-tortuosity graphene after oxidative exfoliating and thermal reducing process.Mean-while,the proteins,sugars,and glycolipids embedded in cytomembrane and cytoderm can in-situ form nanoholes with highly abundant oxygenic groups and heteroatoms around,which can be easily removed and finally the high-tortuosity holey graphene is obtained after a thermal reducing process.The stress distribution after K^(+)intercalation confirms the optimized release of strain caused by the volume change through the finite element method.Benefiting from the unique nanoholes shortening the ion-diffusion length,the synergy of wrinkled and holey structure stabilizing volume fluctuation,and the enhanced electronic conductivity and specific surface area,the high-tortuosity holey graphene demonstrates high reversible capacities of 410 mAh g^(-1)at 25 mA g^(-1)after 150 cycles and retains 91.5%at 2 A g^(-1)after 2500 cycles. 展开更多
关键词 Potassium-ion batteries GRAPHENE High tortuosity Cytomembrane and cytoderm ANODE
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Tuning sodium wettability and pore tortuosity for superior sodium storage 被引量:1
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作者 Yao-Yao Xiao Yi-Hui Liu +4 位作者 Bing-Bing Liu Zhen-Guo Qi You-Bin Zhang Fu-Sheng Liu Guo-Hui Qin 《Rare Metals》 SCIE EI CAS CSCD 2023年第12期4048-4059,共12页
Abundant FeS2 with high theoretical capacity is one of the promising anode candidates in sodium-ion batteries(SlBs),however,the uneven sodium deposition due to the poor interface compatibility and sluggish reaction ki... Abundant FeS2 with high theoretical capacity is one of the promising anode candidates in sodium-ion batteries(SlBs),however,the uneven sodium deposition due to the poor interface compatibility and sluggish reaction kinetics because of the high activation barrier still plague its practical application.Herein,we synthesized the ordered porous carbon matrix wrapped FeS2 nanoparticles(FeS_2@OCN)with high sodium wettability and low pore tortuosity to economically enhance the interface compatibility as well as to lower the energy barrier in SIBs.The synergistic effects of low tortuosity pores and strong sodium wettability homogenize the Na+flux distribution,bring the electron dislocation via the enrichment of edgenitrogen(Pyridinic N and Pyrrolic N),thus achieving the dendrite-free sodium deposition and dramatically enhanced reaction kinetics.Benefiting from exceptional structural/compositional/electronic merits,the resultant anode is endowed with exceptional structure stability,achieving long-term cycling stability of 451.9 mAh·g^(-1)after 1000cycles at 1 A·g^(-1)with specific capacity retention of 92.9%.Attenuated electrode tortuosity and high sodium wettability can corporately improve the interface compatibility and attenuate the activation barrier of the FeS_2 host and beyond. 展开更多
关键词 FeS_2 WETTABILITY Sodium capture Low tortuosity Charge transport
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Retinal Vascular Tortuosity in Hospitalized Patients with Type 2 Diabetes and Diabetic Retinopathy in China 被引量:1
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作者 S. Zhu M. van Triest +4 位作者 M. Tong T. Lamers P. Han W. Qian B. M. ter Haar Romeny 《Journal of Biomedical Science and Engineering》 2016年第10期143-154,共13页
Context: Diabetic patients are at high risk for microvascular complications of disease such as diabetic retinopathy (DR) and diabetic neuropathy. Imaging the retinal micro-vasculature offers a chance to measure quanti... Context: Diabetic patients are at high risk for microvascular complications of disease such as diabetic retinopathy (DR) and diabetic neuropathy. Imaging the retinal micro-vasculature offers a chance to measure quantitatively the microvascular changes in diabetic patients’ onset and progression. However, the relation between retinal biomarkers and diabetic risk factors is unclear in Chinese hospitalized type 2 diabetic patients. Aims: To examine the associations of retinal vascular tortuosity with risk factors of type 2 diabetes and diabetic retinopathy in Chinese hospitalized patients. Patients and Methods: Our cross-sectional study includes 504 participants with type 2 diabetes hospitalized in the department of endocrinology in Shengjing hospital, Shenyang, China. Patients’ socio-demographic, clinical and biological information was retrieved from their ID card, the interview, and the local hospital information system. Retinal photographs were taken by laser-scanning ophthalmoscopy of both eyes and checked if gradable for analysis. The weighted mean and standard deviation of tortuosity were calculated from the retinal photographs using a novel robust and fully automatic quantitative method. DR was assessed from the retinal photographs by the ophthalmologist according to the modified Airlie House classification into No DR and Any DR in our current study. Data were analyzed by SPSS Version 22 with Student’s t test, Mann-Whitney U test, Chi-square test, and linear regression. Results: For the total participants (504) in this study, the weighted mean and standard deviation (SD) of tortuosity was 12.05 × 10?3 (SD: 1.66 × 10?3) and 24.31 × 10?3 (SD: 3.69 × 10?3), respectively. 386 (76.6%) patients were diagnosed with DR who had older age, long duration of diabetes, higher brachial ankle pulse wave velocity (baPWV), higher systolic blood pressure (SBP), higher diastolic blood pressure (DBP), and higher retinal vascular tortuosity values. In univariable linear regression analyses, older age, longer duration, higher baPWV, higher urine microalbuminuria, higher urine albumin/creatinine ratio, diagnosed with high blood pressure, thrombosis or Any DR, were significantly associated with both higher tortuosity measures (all P values 展开更多
关键词 Retinal Vascular tortuosity Diabetic Retinopathy Diabetic Neuropathy Type 2 Diabetes Risk Factor BIOMARKER
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Simulation of the relationship between porosity and tortuosity in porous media with cubic particles
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作者 唐晓武 孙祖峰 程冠初 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第10期1-8,共8页
Tortuosity is an important parameter used in areas such as vascular medicine,neurobiology,and the field of soil permeability and diffusion to express the mass transport in porous media.It is a function of the porosity... Tortuosity is an important parameter used in areas such as vascular medicine,neurobiology,and the field of soil permeability and diffusion to express the mass transport in porous media.It is a function of the porosity and the shape and distribution of particles.In this paper,the tortuosity of cubic particles is calculated.With the assumption that the porous medium is homogeneous,the problem is converted to the micro-level over a unit cell,and geometry models of flow paths are proposed.In three-dimensional(3D) cells,the flow paths are too complicated to define.Hence,the 3D models are converted to two-dimensional(2D) models to simplify the calculation process.It is noticed that the path in the 2D model is shorter than that in the 3D model.As a result,triangular particles and the interaction are also taken into consideration to account for the longer distance respectively.We have proposed quadrate particle and interaction(QI) and quadrate and triangular particle(QT) models with cubic particles.Both models have shown good agreement with the experimental data.It is also found that they can predict the toruosities of some kinds of porous media,like freshwater sediment and Negev chalk. 展开更多
关键词 tortuosity POROSITY porous media cubic particles
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Manufacturing Water-Based Low-Tortuosity Electrodes for Fast-Charge through Pattern Integrated Stamping
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作者 Haoze Ren Ying Wang +4 位作者 Daxian Cao William Gedney Tongtai Ji Xiao Sun Hongli Zhu 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第4期121-128,共8页
Achieving high energy density and fast charging of lithium-ion batteries can accelerate the promotion of electric vehicles.However,the increased mass loading causes poor charge transfer,impedes the electrochemical rea... Achieving high energy density and fast charging of lithium-ion batteries can accelerate the promotion of electric vehicles.However,the increased mass loading causes poor charge transfer,impedes the electrochemical reaction kinetics,and limits the battery charging rate.Herein,this work demonstrated a novel pattern integrated stamping process for creating channels in the electrode,which benefits ion transport and increases the rate performance of the electrode.Meanwhile,the pressure applied during the stamping process improved the contact between electrode and current collector and also enhanced the mechanical stability of the electrode.Compared to the conventional bar-coated electrode with the same thickness of 155μm(delivered a discharge capacity of 16 mAh g^(−1) at the rate of 3 C),the stamped low-tortuosity LiFePO_(4) electrode delivered 101 mAh g^(−1) capacity.Additionally,water was employed as a solvent in this study.Owing to its eco-friendliness,high scalability,and minimal waste generation,this novel stamping technique inspire a new method for the industrial-level efficient roll to roll fabrication of fast-charge electrodes. 展开更多
关键词 fast charging KINETIC lithium-ion batteries tortuosity water solvent
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Relationship between Coronary Artery Tortuosity and Cardiorespiratory Fitness in Patients without Obstructed Coronaries
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作者 Wan-jun LIU Menaka DHUROMSINGH +4 位作者 Xing-wei HE Yang XIE Xiao-lei LIU Hong-jie WANG He-song ZENG 《Current Medical Science》 SCIE CAS 2022年第5期941-948,共8页
Objective This study aimed to analyze the relationship between cardiorespiratory fitness(CRF)and the increasing severity of coronary artery tortuosity(CAT)in patients with non-stenosed coronaries.Methods A total of 39... Objective This study aimed to analyze the relationship between cardiorespiratory fitness(CRF)and the increasing severity of coronary artery tortuosity(CAT)in patients with non-stenosed coronaries.Methods A total of 396 patients who underwent coronary angiography and cardiopulmonary exercise testing(CPET)between August 2020 and July 2021 were included in this single-center retrospective study after excluding patients with significant coronary artery disease(≥50%stenosis).Patients were divided into two groups:no or mild coronary artery tortuosity(N/M-CAT)and moderate to severe coronary artery tortuosity(M/S-CAT)and laboratory electrocardiographic,echocardiographic,and CPET parameters were compared between two groups.Results M/S-CAT was found in 46.9%of the study participants,with 66.7%being women.M/S-CAT was significantly associated with advanced age(P=0.014)and females(P=0.001).Diastolic dysfunction parameters,E velocity(P=0.011),and E/A ratio(P=0.004)also revealed significant differences between the M/S-CAT group and N/M-CAT group.VO2@peak(1.22±0.39 vs.1.07±0.39,P<0.01)and VO2@AT(0.77±0.22 vs.0.71±0.21,P=0.017)were significantly lower in the M/S-CAT group than in the N/M-CAT group.Multivariate logistic regression analysis identified females(OR=0.448;95%CI,0.296–0.676;P=0.000)and E/A ratio(OR=0.307;95%CI,0.139–0.680;P=0.004)to be independent risk factors of M/S-CAT and showed no association of CPET parameters to M/S-CAT.Conclusion The results indicate that increasing severity of CAT is strongly associated with female gender and E/A ratio and is not directly correlated with decreasing CRF.Further research with a larger patient population and a longer follow-up time is required to fully comprehend the impact of CAT on CRF. 展开更多
关键词 coronary angiography coronary artery tortuosity cardiopulmonary exercise testing left ventricular dysfunction
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Mathematical Model of a Hyperbolic Hydraulic Fracture with Tortuosity
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作者 M. R. R. Kgatle-Maseko D. P. Mason 《Journal of Applied Mathematics and Physics》 2021年第5期1121-1157,共37页
The aim of the research is to study the propagation of a hydraulic fracture with tortuosity due to contact areas between touching asperities on opposite crack walls. The tortuous fracture is replaced by a model symmet... The aim of the research is to study the propagation of a hydraulic fracture with tortuosity due to contact areas between touching asperities on opposite crack walls. The tortuous fracture is replaced by a model symmetric partially open fracture with a hyperbolic crack law and a modified Reynolds flow law. The normal stress at the crack walls is assumed to be proportional to the half-width of the model fracture. The Lie point symmetry of the nonlinear diffusion equation for the fracture half-width is derived and the general form of the group invariant solution is obtained. It was found that the fluid flux at the fracture entry cannot be prescribed arbitrarily, because it is determined by the group invariant solution and that the exponent n in the modified Reynolds flow power law must lie in the range 2 < <em>n</em> < 5. The boundary value problem is solved numerically using a backward shooting method from the fracture tip, offset by 0 < <em>δ</em> <span style="white-space:nowrap;">&#8810;</span> 1 to avoid singularities, to the fracture entry. The numerical results showed that the tortuosity and the pressure due to the contact regions both have the effect of increasing the fracture length. The spatial gradient of the half-width was found to be singular at the fracture tip for 3 < <em>n</em> < 5, to be finite for the Reynolds flow law <em>n</em> = 3 and to be zero for 2 < <em>n</em> < 3. The thin fluid film approximation breaks down at the fracture tip for 3 < <em>n</em> < 5 while it remains valid for increasingly tortuous fractures with 2 < <em>n</em> < 3. The effect of the touching asperities is to decrease the width averaged fluid velocity. An approximate analytical solution for the half-width, which was found to agree well with the numerical solution, is derived by making the approximation that the width averaged fluid velocity increases linearly with distance along the fracture. 展开更多
关键词 Hyperbolic Crack Law Partially Open Fracture with tortuosity Modified Reynolds Flow Law Backward Shooting Method Approximate Analytical Solution
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Tortuosity regulation of two-dimensional nanofluidic films for water evaporation-induced electricity generation 被引量:1
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作者 Zhihang Liu Chao Liu +7 位作者 Anqi Ni Kunpeng Mao Long Chen Liang Xue Jingwen Sun Xin Wang Pan Xiong Junwu Zhu 《Nano Research》 SCIE EI CSCD 2024年第7期6192-6202,共11页
Water evaporation-induced electricity generation is a promising technology for renewable energy harvesting.However,the output power of some reported two-dimensional(2D)nanofluidic films is still restricted by the rela... Water evaporation-induced electricity generation is a promising technology for renewable energy harvesting.However,the output power of some reported two-dimensional(2D)nanofluidic films is still restricted by the relatively weak water–solid interactions within the tortuous nanochannels.To further enhance the comprehension and utilization of water–solid interactions,it is of utmost importance to conduct an in-depth investigation and propose a regulatory concept encompassing ion transport.Herein,we propose tortuosity regulation of 2D nanofluidic titanium oxide(Ti_(0.87)O_(2))films to optimize the ion transport within the interlayer nanochannel for enhanced efficiency in water evaporation-induced electricity generation for the first time.The significance of tortuosity in ion transport is elucidated by designing three 2D nanofluidic films with different tortuosity.Tortuosity analysis and in situ Raman measurement demonstrate that low tortuosity can facilitate the formation of efficient pathways for hydrated proton transport and promote water–solid interactions.Consequently,devices fabricated with the optimized 2D nanofluidic films exhibited a significantly enhanced output power density of approximately 204.01μW·cm^(−2),far exceeding those prepared by the high-tortuosity 2D nanofluidic films.This work highlights the significance of the construction of low tortuosity channels for 2D nanofluidic films with excellent performance. 展开更多
关键词 water evaporation-induced electricity generation tortuosity ion transport two-dimensional nanofluidic films
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Numerical study on the effective thermal conductivity and thermal tortuosity of porous media with different morphologies
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作者 DU Shen LI Dong +1 位作者 LI Meng-Jie HE Ya-Ling 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2024年第6期1685-1694,共10页
Effective thermal conductivity and thermal tortuosity are crucial parameters for evaluating the effectiveness of heat conduction within porous media.The direct pore-scale numerical simulation method is applied to inve... Effective thermal conductivity and thermal tortuosity are crucial parameters for evaluating the effectiveness of heat conduction within porous media.The direct pore-scale numerical simulation method is applied to investigate the heat conduction processes inside porous structures with different morphologies.The thermal conduction performances of idealized porous structures are directly compared with real foams across a wide range of porosity.Real foam structures are reconstructed using X-ray computed tomography and image processing techniques,while Kelvin and Weaire-Phelan structures are generated through periodic unit cell reconstruction.The detailed temperature fields inside the porous structures are determined by solving the heat conduction equation at the pore scale.The results present that the equivalent thermal conductivity of Kelvin and Weaire-Phelan structures is similar to and greater than that of the real foam structure with the same strut porosity.The thermal tortuosity of real foam structure is relatively larger and the heat conduction path becomes straighter by adopting the anisotropic design.The thermal tortuosity of the fluid channels for Kelvin,Weaire-Phelan,and real foam structures is close to one.The thermal conductivity of porous structures with heat transfer fluid increases as the thermal conductivity ratio of fluid to solid becomes larger.A small porosity of porous media leads to a larger equivalent thermal conductivity due to the dominant contribution of porous skeleton in the heat conduction process.Correlations derived from parallel and series models,as well as the Maxwell-Eucken models,provide decent predictions of effective thermal conductivity,with an average error of less than 8%in the entire range of thermal conductivity ratio. 展开更多
关键词 volumetric solar receiver porous morphology direct pore-scale simulation equivalent thermal conductivity thermal tortuosity empirical correlation
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Effects of grain's shape-and size-polydispersities,orientation,and area fraction on tortuosity and permeability of 2D granular media
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作者 Ke Cao Huisu Chen +2 位作者 Mohammad Iqbal Khan Mingqi Li Lin Liu 《Particuology》 SCIE EI CAS CSCD 2024年第7期535-557,共23页
The microstructure of granular media, including grain's shape- and size-polydispersities, orientation, and area fraction can potentially affect its permeability. However, few studies consider the coupling effects ... The microstructure of granular media, including grain's shape- and size-polydispersities, orientation, and area fraction can potentially affect its permeability. However, few studies consider the coupling effects of these features. This work employs geometrical probability and stereology to establish quantitative relationships between the above microstructural features and the geometric tortuosity of the two-dimensional granular media containing superellipse, superoval, and polygon grains. Then the lattice Boltzmann method (LBM) is used to determine the permeabilities of these granular media. By combining the tortuosity model and the LBM-derived permeabilities, modified K–C equations are formulated to predict the permeability and the shape factor, considering the grain's shape- and size-polydispersities, orientation, and area fraction. The reliability of these methods can be verified by comparing them with both our simulations and available experimental, theoretical, and numerical data reported in the literature. The findings implicate that the tortuosity and permeability of the granular media are strongly correlated with the grain's shape, orientation, and area fraction but unaffected by the size polydispersity and spatial arrangement of grains. Only circularity is not enough to derive a unified formula for considering the impact of grain shape on tortuosity and permeability, other shape parameters need to be explored in the future. 展开更多
关键词 Geometric tortuosity Konzey-Carman equation Shape and size ploydispersities Grain orientation Lattice Boltzmann method Granular media
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Insights into adsorbent tortuosity across aqueous adsorption systems
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作者 Ackmez Mudhoo Marta Otero Khim Hoong Chu 《Particuology》 SCIE EI CAS CSCD 2024年第5期71-88,共18页
Pore network,pore connectivity,and the resulting effective adsorbate pore diffusivity within an adsorbent are critical physical considerations in mass transport modeling of aqueous adsorption.Tied to these three adsor... Pore network,pore connectivity,and the resulting effective adsorbate pore diffusivity within an adsorbent are critical physical considerations in mass transport modeling of aqueous adsorption.Tied to these three adsorbent features are the adsorbent tortuosity and tortuosity factor concepts.These concepts encompass the collective hindrance to intra-adsorbent adsorbate transport arising because of a disorderly adsorbent porous topology.It is crucial for materials scientists,chemists,chemical engineers,and water treatment specialists to understand the complex and variable connections among adsorbate chemistry,adsorbent chemistry,adsorbent porosity,pore shape,size,and tortuosity,pore wall effect,adsorbate-adsorbent interactions,and adsorbate-adsorbate interactions in competitively contaminated aqueous environments.Adsorbent tortuosity has been sporadically studied in aqueous adsorption models.Despite the small population of these studies,insightful observations and inferences have been reported.However,as it appears,no review has been published to compile,compare,and contrast these aspects.Hence,this review concisely brings up those observations and interpretations around adsorbent tortuosity for aqueous adsorption systems.The notion of an adsorbent's tortuosity being single-valued is argued to be imprecise.Finally,perspectives are aired on possible research and development directions for elucidating the dynamic attributes of adsorbent tortuosity and applying them in real-scale adsorption-oriented water purification.The data acquired by filling in these research gaps can enable the design of adsorbents more adapted for real-scale water purification. 展开更多
关键词 ADSORBENT tortuosity POROSITY Pore diffusion models Aqueous systems
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Quantitative characterization of types 1 and 2 macular neovascularization in neovascular age-related macular degeneration with intravitreal conbercept:an analysis utilizing optical coherence tomography angiography
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作者 Yan-Mei Shi Xiao Xie +7 位作者 Wen-Qi Wang Xiao-Meng Yuan Zhi-Ping Zhang Hong-Yan Wang Jie Meng Ze-Hao Kong Xia Jing Ting-Ting Liu 《International Journal of Ophthalmology(English edition)》 2025年第8期1490-1497,共8页
AIM:To quantitatively assess central macular thickness(CMT),macular neovascularization(MNV)area,vascular tortuosity(VT),and vascular dispersion(VDisp)in neovascular age-related macular degeneration(nAMD),type 1 and ty... AIM:To quantitatively assess central macular thickness(CMT),macular neovascularization(MNV)area,vascular tortuosity(VT),and vascular dispersion(VDisp)in neovascular age-related macular degeneration(nAMD),type 1 and type 2 MNV,by means of optical coherence tomography(OCT)and OCT angiography(OCTA)techniques.METHODS:In this retrospective and observational case series,patients were classified into type 1 or type 2 MNV groups.A comprehensive panel of OCT and OCTA metrics was evaluated,including CMT,MNV area,VT,and VDisp.All subjects underwent a standardized intravitreal conbercept(IVC)regimen[3+pro re nata(PRN)]with a 12-month follow-up.MNV area was obtained by manual measurements with OCTA software,and VT and VDisp were calculated by automated analysis with Image J software.RESULTS:A total of 101 participants were included,with 51 patients in the type 1 MNV group(mean age 67.32±9.12y)and 50 patients in the type 2 MNV group(mean age 64.74±5.21y).The mean number of IVC injections was 3.98±1.53 for type 1 MNV and 3.73±0.81 for type 2 MNV.Both subtypes exhibited significant improvements in visual acuity,accompanied by marked reductions in CMT and MNV area(P<0.05)at 12mo after treatment.In type 2 MNV,VT significantly decreased(P<0.05),whereas no significant change was observed in VT for type 1 MNV.VDisp did not significantly changed in either sybtypes.Moreover,in type 1 MNV,final best-corrected visual acuity(BCVA)using logMAR correlated positively with both pre-and post-treatment CMT,while in type 2 MNV,a significant positive correlation was found between the number of injections and final CMT.CONCLUSION:This study shows that conbercept treatment significantly improves visual acuity and macular structure in both type 1 and type 2 MNV with reductions in CMT and MNV area.The significant reduction in VT in type 2 MNV suggests its potential as a biomarker for disease activity.The findings imply the quantitative assessment useful for the stratification,prognostication,and personalized management of MNV in nAMD. 展开更多
关键词 macular neovascularization age-related macular degeneration optical coherence tomography angiography conbercept vessel tortuosity vessel dispersion
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The impact of follicle-stimulating hormone and the sperm concentration on the success of varicocelectomy
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作者 Li-Hong Wang Lei Zheng +1 位作者 Hui Jiang Tao Jiang 《Asian Journal of Andrology》 2025年第5期657-658,共2页
Dear Editor,Varicocele(VC)is a vascular condition characterized by abnormal tortuosity and dilation of the pampiniform plexus veins within the spermatic cord.VC is commonly observed in young adults,predominantly on th... Dear Editor,Varicocele(VC)is a vascular condition characterized by abnormal tortuosity and dilation of the pampiniform plexus veins within the spermatic cord.VC is commonly observed in young adults,predominantly on the left side;it is a frequent cause of male infertility and can lead to testicular hypofunction,pain,and discomfort.Microsurgical varicocelectomy is the gold standard for treating infertility caused by VC.VC repair is strongly recommended for couple infertility,oligoasthenoteratozoospermia(OAT),Grade 2 or 3 clinical VC,partner age<37 years,patient age<40 years,or testicular hypotrophy in children and adolescents. 展开更多
关键词 vascular condition follicle stimulating hormone treating infertility pampiniform plexus veins abnormal tortuosity dilation pampiniform plexus veins VARICOCELECTOMY male infertility microsurgical varicocelectomy
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Armoring hydrophilic wood-structured ultrathick electrode with bimetallic nitride enables high energy-density supercapacitor
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作者 Nannan Ming Jikun Xu +2 位作者 Jingfang Lei Cankun Hu Kaifu Huo 《Green Energy & Environment》 2025年第2期345-357,共13页
Thick electrodes can reduce the ratio of inactive constituents in a holistic energy storage system while improving energy and power densities.Unfortunately,traditional slurry-casting electrodes induce high-tortuous io... Thick electrodes can reduce the ratio of inactive constituents in a holistic energy storage system while improving energy and power densities.Unfortunately,traditional slurry-casting electrodes induce high-tortuous ionic diffusion routes that directly depress the capacitance with a thickening design.To overcome this,a novel 3D low-tortuosity,self-supporting,wood-structured ultrathick electrode(NiMoN@WC,a thickness of~1400 mm)with hierarchical porosity and artificial array-distributed small holes was constructed via anchoring bimetallic nitrides into the monolithic wood carbons.Accompanying the embedded NiMoN nanoclusters with well-designed geometric and electronic structure,the vertically low-tortuous channels,enlarged specific surface area and pore volume,superhydrophilic interface,and excellent charge conductivities,a superior capacitance of NiMoN@WC thick electrodes(~5350 mF cm^(-2)and 184.5 F g^(-1))is achieved without the structural deformation.In especial,monolithic wood carbons with gradient porous network not only function as the high-flux matrices to ameliorate the NiMoN loading via cell wall engineering but also allow fully-exposed electroactive substance and efficient current collection,thereby deliver an acceptable rate capability over 75%retention even at a high sweep rate of 20 mA cm^(-2).Additionally,an asymmetric NiMoN@WC//WC supercapacitor with an available working voltage of 1.0-1.8 V is assembled to demonstrate a maximum energy density of~2.04 mWh cm^(-2)(17.4 Wh kg^(-1))at a power density of 1620 mW cm^(-2),along with a decent long-term lifespan over 10,000 charging-discharging cycles.As a guideline,the rational design of wood ultrathick electrode with nanostructured transition metal nitrides sketch a promising blueprint for alleviating global energy scarcity while expanding carbon-neutral technologies. 展开更多
关键词 Wood-structured thick electrode Supercapacitors Transition metal nitrides Low tortuosity
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Coronary tortuosity is associated with reversible myocardial perfusion defects in patients without coronary artery disease 被引量:8
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作者 LI Yang LIU Nai-feng +5 位作者 GU Zhong-ze CHEN Yong LU Jun FENG Yi MA Gen-shan SHEN Cheng-xing 《Chinese Medical Journal》 SCIE CAS CSCD 2012年第19期3581-3583,共3页
Coronary artery disease (CAD) is the leading cause of cardiovascular death in the Chinese population.Coronary angiography is the golden standard for the diagnosis of CAD and coronary tortuosity (CT) is a common co... Coronary artery disease (CAD) is the leading cause of cardiovascular death in the Chinese population.Coronary angiography is the golden standard for the diagnosis of CAD and coronary tortuosity (CT) is a common coronary angiographic finding, however, little work has been done on clinical manifestation and significance of CT. It was hypothesized that CT may be associated with angina pectoris and abnormal exercise stress test in patients without CAD, but weather CT can lead to cardiac ischemia has not yet been clarified. The purpose of this study was to determine the impact of CT on myocardial perfusion detects. 展开更多
关键词 coronary tortuosity cardiac ischemia myocardial perfusion defects coronary pressure
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