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15 nm Bulk nFinFET器件性能研究及参数优化
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作者 侯天昊 范杰清 +3 位作者 赵强 张芳 郝建红 董志伟 《强激光与粒子束》 CAS CSCD 北大核心 2024年第3期92-99,共8页
为研究Bulk FinFET工作时基本结构参数、器件温度和栅极材料对其性能的影响,建立了一个15 nm n型Bulk FinFET器件模型,仿真分析了不同栅长、鳍宽、鳍高、沟道掺杂浓度、器件工作温度、栅极材料对器件性能的影响,发现增长栅长、降低鳍宽... 为研究Bulk FinFET工作时基本结构参数、器件温度和栅极材料对其性能的影响,建立了一个15 nm n型Bulk FinFET器件模型,仿真分析了不同栅长、鳍宽、鳍高、沟道掺杂浓度、器件工作温度、栅极材料对器件性能的影响,发现增长栅长、降低鳍宽和增加鳍高有助于抑制短沟道效应;1×10^(17)cm^(-3)以下的低沟道掺杂浓度对器件特性影响不大,但高掺杂会使器件失效;器件工作温度的升高会导致器件性能的下降;采用高K介质材料作为栅极器件性能优于传统材料SiO_(2)。 展开更多
关键词 bulk FinFET 短沟道效应 器件性能 参数优化 栅极材料
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袋型阻尼密封动力学特性双控制体Bulk Flow模型
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作者 桂佳强 李志刚 李军 《西安交通大学学报》 EI CAS CSCD 北大核心 2024年第7期26-38,共13页
为快速准确预测袋型阻尼密封泄漏特性和动力学特性,针对传统单控制体Bulk Flow模型预测精度低、无法预测交叉动力系数的问题,提出了袋型阻尼密封双控制体Bulk Flow模型和动力学特性数值预测方法,并开发了计算程序。首先,依据边界层理论... 为快速准确预测袋型阻尼密封泄漏特性和动力学特性,针对传统单控制体Bulk Flow模型预测精度低、无法预测交叉动力系数的问题,提出了袋型阻尼密封双控制体Bulk Flow模型和动力学特性数值预测方法,并开发了计算程序。首先,依据边界层理论,将袋型密封腔室划分为两个控制体,推导了控制体的连续性、周向动量和能量方程,引入Swamee-Jain和Takahashi方程,计算流体-壁面间和流体-流体间的周向黏性摩擦力;其次,采用牛顿-拉夫森算法和摄动分析法分别求解0阶和1阶控制方程,获得各刚度、阻尼动力特性系数;然后,通过与袋型阻尼密封泄漏量和动力特性系数的实验值、单控制体Bulk Flow模型和非定常计算流体动力学(CFD)数值结果进行比较,验证了模型和方法的准确性和可靠性;最后,研究了转子转速(10 000、15 000、20 000 r/min)和预旋比(0.067、0.724、0.997)对袋型阻尼密封动力学特性的影响。结果表明:所发展的模型和方法具有计算速度快、预测精度高(泄漏量预测误差小于6%,动力特性系数预测误差小于38%)的优点;转子转速和进口预旋的增大均会导致袋型阻尼密封有效阻尼显著减小,穿越频率显著增大,易诱发轴系失稳。 展开更多
关键词 袋型阻尼密封 泄漏特性 动力学特性 双控制体 bulk Flow模型
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Grain yield and N uptake of maize in response to increased plant density under reduced water and nitrogen supply conditions 被引量:3
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作者 Jingui Wei Qiang Chai +5 位作者 Wen Yin Hong Fan Yao Guo Falong Hu Zhilong Fan QimingWang 《Journal of Integrative Agriculture》 SCIE CSCD 2024年第1期122-140,共19页
The development of modern agriculture requires the reduction of water and chemical N fertilizer inputs.Increasing the planting density can maintain higher yields,but also consumes more of these restrictive resources.H... The development of modern agriculture requires the reduction of water and chemical N fertilizer inputs.Increasing the planting density can maintain higher yields,but also consumes more of these restrictive resources.However,whether an increased maize density can compensate for the negative effects of reduced water and N supply on grain yield and N uptake in the arid irrigated areas remains unknown.This study is part of a long-term positioning trial that started in 2016.A split-split plot field experiment of maize was implemented in the arid irrigated area of northwestern China in 2020 to 2021.The treatments included two irrigation levels:local conventional irrigation reduced by 20%(W1,3,240 m^(3)ha^(-1))and local conventional irrigation(W2,4,050 m^(3)ha^(-1));two N application rates:local conventional N reduced by 25%(N1,270 kg ha^(-1))and local conventional N(360 kg ha^(-1));and three planting densities:local conventional density(D1,75,000 plants ha^(-1)),density increased by 30%(D2,97,500 plants ha-1),and density increased by 60%(D3,120,000 plants ha^(-1)).Our results showed that the grain yield and aboveground N accumulation of maize were lower under the reduced water and N inputs,but increasing the maize density by 30% can compensate for the reductions of grain yield and aboveground N accumulation caused by the reduced water and N supply.When water was reduced while the N application rate remained unchanged,increasing the planting density by 30% enhanced grain yield by 13.9% and aboveground N accumulation by 15.3%.Under reduced water and N inputs,increasing the maize density by 30% enhanced N uptake efficiency and N partial factor productivity,and it also compensated for the N harvest index and N metabolic related enzyme activities.Compared with W2N2D1,the N uptake efficiency and N partial factor productivity increased by 28.6 and 17.6%under W1N1D2.W1N2D2 had 8.4% higher N uptake efficiency and 13.9% higher N partial factor productivity than W2N2D1.W1N2D2 improved urease activity and nitrate reductase activity by 5.4% at the R2(blister)stage and 19.6% at the V6(6th leaf)stage,and increased net income and the benefit:cost ratio by 22.1 and 16.7%,respectively.W1N1D2 and W1N2D2 reduced the nitrate nitrogen and ammoniacal nitrogen contents at the R6 stage in the 40-100 cm soil layer,compared with W2N2D1.In summary,increasing the planting density by 30% can compensate for the loss of grain yield and aboveground N accumulation under reduced water and N inputs.Meanwhile,increasing the maize density by 30% improved grain yield and aboveground N accumulation when water was reduced by 20% while the N application rate remained constant in arid irrigation areas. 展开更多
关键词 water and N reduction plant density MAIZE grain yield N uptake compensation effect
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The Probability Density Function Related to Shallow Cumulus Entrainment Rate and Its Influencing Factors in a Large-Eddy Simulation 被引量:3
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作者 Lei ZHU Chunsong LU +5 位作者 Xiaoqi XU Xin HE Junjun LI Shi LUO Yuan WANG Fan WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第1期173-187,共15页
The process of entrainment-mixing between cumulus clouds and the ambient air is important for the development of cumulus clouds.Accurately obtaining the entrainment rate(λ)is particularly important for its parameteri... The process of entrainment-mixing between cumulus clouds and the ambient air is important for the development of cumulus clouds.Accurately obtaining the entrainment rate(λ)is particularly important for its parameterization within the overall cumulus parameterization scheme.In this study,an improved bulk-plume method is proposed by solving the equations of two conserved variables simultaneously to calculateλof cumulus clouds in a large-eddy simulation.The results demonstrate that the improved bulk-plume method is more reliable than the traditional bulk-plume method,becauseλ,as calculated from the improved method,falls within the range ofλvalues obtained from the traditional method using different conserved variables.The probability density functions ofλfor all data,different times,and different heights can be well-fitted by a log-normal distribution,which supports the assumed stochastic entrainment process in previous studies.Further analysis demonstrate that the relationship betweenλand the vertical velocity is better than other thermodynamic/dynamical properties;thus,the vertical velocity is recommended as the primary influencing factor for the parameterization ofλin the future.The results of this study enhance the theoretical understanding ofλand its influencing factors and shed new light on the development ofλparameterization. 展开更多
关键词 large-eddy simulation cumulus clouds entrainment rate probability density functions spatial and temporal distribution
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Evolutionary history shapes variation of wood density of tree species across the world 被引量:1
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作者 Fangbing Li Hong Qian +7 位作者 Jordi Sardans Dzhamal Y.Amishev Zixuan Wang Changyue Zhang Tonggui Wu Xiaoniu Xu Xiao Tao Xingzhao Huang 《Plant Diversity》 SCIE CAS CSCD 2024年第3期283-293,共11页
The effect of evolutionary history on wood density variation may play an important role in shaping variation in wood density,but this has largely not been tested.Using a comprehensive global dataset including 27,297 m... The effect of evolutionary history on wood density variation may play an important role in shaping variation in wood density,but this has largely not been tested.Using a comprehensive global dataset including 27,297 measurements of wood density from 2621 tree species worldwide,we test the hypothesis that the legacy of evolutionary history plays an important role in driving the variation of wood density among tree species.We assessed phylogenetic signal in different taxonomic(e.g.,angiosperms and gymnosperms)and ecological(e.g.,tropical,temperate,and boreal)groups of tree species,explored the biogeographical and phylogenetic patterns of wood density,and quantified the relative importance of current environmental factors(e.g.,climatic and soil variables)and evolutionary history(i.e.,phylogenetic relatedness among species and lineages)in driving global wood density variation.We found that wood density displayed a significant phylogenetic signal.Wood density differed among different biomes and climatic zones,with higher mean values of wood density in relatively drier regions(highest in subtropical desert).Our study revealed that at a global scale,for angiosperms and gymnosperms combined,phylogeny and species(representing the variance explained by taxonomy and not direct explained by long-term evolution process)explained 84.3%and 7.7%of total wood density variation,respectively,whereas current environment explained 2.7%of total wood density variation when phylogeny and species were taken into account.When angiosperms and gymnosperms were considered separately,the three proportions of explained variation are,respectively,84.2%,7.5%and 6.7%for angiosperms,and 45.7%,21.3%and 18.6%for gymnosperms.Our study shows that evolutionary history outpaced current environmental factors in shaping global variation in wood density. 展开更多
关键词 Wood density PHYLOGENY ANGIOSPERMS GYMNOSPERMS Climate factors Biophysical parameters
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Recent advances in high charge density triboelectric nanogenerators 被引量:1
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作者 Xin Cui Jiaheng Nie Yan Zhang 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2024年第4期1-19,共19页
Triboelectric materials with high charge density are the building-block for the commercial application of triboelectric nanogenerators(TENGs).Unstable dynamic processes influence the change of the charge density on th... Triboelectric materials with high charge density are the building-block for the commercial application of triboelectric nanogenerators(TENGs).Unstable dynamic processes influence the change of the charge density on the surface and inside of triboelectric materials.The charge density of triboelectric materials depends on the surface and the internal charge transfer processes.The focus of this review is on recent advances in high charge density triboelectric materials and advances in the fabrication of TENGs.We summarize the existing strategies for achieving high charge density in triboelectric materials as well as their fundamental properties.We then review current optimization methods for regulating dynamic charge transfer processes to increase the output charge density:first,increasing charge injection and limiting charge dissipation to achieve a high average surface charge density,and second,regulating the internal charge transfer process and storing charge in triboelectric materials to increase the output charge density.Finally,we present the challenges and prospects in developing high-performance triboelectric materials. 展开更多
关键词 triboelectric nanogenerator charge density charge transfer charge store
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A facile strategy for tuning the density of surface-grafted biomolecules for melt extrusion-based additive manufacturing applications 被引量:1
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作者 I.A.O.Beeren G.Dos Santos +8 位作者 P.J.Dijkstra C.Mota J.Bauer H.Ferreira Rui L.Reis N.Neves S.Camarero-Espinosa M.B.Baker L.Moroni 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2024年第3期277-291,共15页
Melt extrusion-based additive manufacturing(ME-AM)is a promising technique to fabricate porous scaffolds for tissue engi-neering applications.However,most synthetic semicrystalline polymers do not possess the intrinsi... Melt extrusion-based additive manufacturing(ME-AM)is a promising technique to fabricate porous scaffolds for tissue engi-neering applications.However,most synthetic semicrystalline polymers do not possess the intrinsic biological activity required to control cell fate.Grafting of biomolecules on polymeric surfaces of AM scaffolds enhances the bioactivity of a construct;however,there are limited strategies available to control the surface density.Here,we report a strategy to tune the surface density of bioactive groups by blending a low molecular weight poly(ε-caprolactone)5k(PCL5k)containing orthogonally reactive azide groups with an unfunctionalized high molecular weight PCL75k at different ratios.Stable porous three-dimensional(3D)scaf-folds were then fabricated using a high weight percentage(75 wt.%)of the low molecular weight PCL 5k.As a proof-of-concept test,we prepared films of three different mass ratios of low and high molecular weight polymers with a thermopress and reacted with an alkynated fluorescent model compound on the surface,yielding a density of 201-561 pmol/cm^(2).Subsequently,a bone morphogenetic protein 2(BMP-2)-derived peptide was grafted onto the films comprising different blend compositions,and the effect of peptide surface density on the osteogenic differentiation of human mesenchymal stromal cells(hMSCs)was assessed.After two weeks of culturing in a basic medium,cells expressed higher levels of BMP receptor II(BMPRII)on films with the conjugated peptide.In addition,we found that alkaline phosphatase activity was only significantly enhanced on films contain-ing the highest peptide density(i.e.,561 pmol/cm^(2)),indicating the importance of the surface density.Taken together,these results emphasize that the density of surface peptides on cell differentiation must be considered at the cell-material interface.Moreover,we have presented a viable strategy for ME-AM community that desires to tune the bulk and surface functionality via blending of(modified)polymers.Furthermore,the use of alkyne-azide“click”chemistry enables spatial control over bioconjugation of many tissue-specific moieties,making this approach a versatile strategy for tissue engineering applications. 展开更多
关键词 Additive manufacturing BLENDING Surface functionalization Surface density Click chemistry HUMAN
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Flexible,high-density,laminated ECoG electrode array for high spatiotemporal resolution foci diagnostic localization of refractory epilepsy 被引量:1
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作者 Yafeng Liu Zhouheng Wang +4 位作者 Yang Jiao Ying Chen Guangyuan Xu Yinji Ma Xue Feng 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2024年第4期388-398,共11页
High spatiotemporal resolution brain electrical signals are critical for basic neuroscience research and high-precision focus diagnostic localization,as the spatial scale of some pathologic signals is at the submillim... High spatiotemporal resolution brain electrical signals are critical for basic neuroscience research and high-precision focus diagnostic localization,as the spatial scale of some pathologic signals is at the submillimeter or micrometer level.This entails connecting hundreds or thousands of electrode wires on a limited surface.This study reported a class of flexible,ultrathin,highdensity electrocorticogram(ECoG)electrode arrays.The challenge of a large number of wiring arrangements was overcome by a laminated structure design and processing technology improvement.The flexible,ultrathin,high-density ECoG electrode array was conformably attached to the cortex for reliable,high spatial resolution electrophysiologic recordings.The minimum spacing between electrodes was 15μm,comparable to the diameter of a single neuron.Eight hundred electrodes were prepared with an electrode density of 4444 mm^(-2).In focal epilepsy surgery,the flexible,high-density,laminated ECoG electrode array with 36 electrodes was applied to collect epileptic spike waves inrabbits,improving the positioning accuracy of epilepsy lesions from the centimeter to the submillimeter level.The flexible,high-density,laminated ECoG electrode array has potential clinical applications in intractable epilepsy and other neurologic diseases requiring high-precision electroencephalogram acquisition. 展开更多
关键词 Electrocorticogram(ECoG)electrode EPILEPSY High density High resolution Laminated structure
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Method to measure tree-ring width,density,elemental composition,and stable carbon and oxygen isotopes using one sample 被引量:1
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作者 Chenxi Xu Yaru Zhao +4 位作者 Wenling An Qingyu Zhao Yucheng Liu Masaki Sano Takeshi Nakatsuka 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第3期167-174,共8页
Tree-ring width(RW),density,elemental com-position,and stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)are widely used as proxies to assess climate change,ecology,and environmental pollution;however,a specific pret... Tree-ring width(RW),density,elemental com-position,and stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)are widely used as proxies to assess climate change,ecology,and environmental pollution;however,a specific pretreat-ment has been needed for each proxy.Here,we developed a method by which each proxy can be measured in the same sample.First,the sample is polished for ring width meas-urement.After obtaining the ring width data,the sample is cut to form a 1-mm-thick wood plate.The sample is then mounted in a vertical sample holder,and gradually scanned by an X-ray beam.Simultaneously,the count rates of the fluorescent photons of elements(for chemical characteriza-tion)and a radiographic grayscale image(for wood density)are obtained,i.e.the density and the element content are obtained.Then,cellulose is isolated from the 1-mm wood plate by removal of lignin,and hemicellulose.After producing this cellulose plate,cellulose subsamples are separated by knife under the microscope for inter-annual and intra-annual stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)analysis.Based on this method,RW,density,elemental composition,δ^(13)C,and δ^(18)O can be measured from the same sample,which reduces sample amount and treatment time,and is helpful for multi-proxy comparison and combination research. 展开更多
关键词 Tree-ring width Tree-ring density Tree-ring elemental composition Tree-ring stable carbon and oxygenisotopes
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Multilevel carbon architecture of subnanoscopic silicon for fast‐charging high‐energy‐density lithium‐ion batteries 被引量:1
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作者 Meisheng Han Yongbiao Mu +2 位作者 Lei Wei Lin Zeng Tianshou Zhao 《Carbon Energy》 SCIE EI CAS CSCD 2024年第4期256-268,共13页
Silicon(Si)is widely used as a lithium‐ion‐battery anode owing to its high capacity and abundant crustal reserves.However,large volume change upon cycling and poor conductivity of Si cause rapid capacity decay and p... Silicon(Si)is widely used as a lithium‐ion‐battery anode owing to its high capacity and abundant crustal reserves.However,large volume change upon cycling and poor conductivity of Si cause rapid capacity decay and poor fast‐charging capability limiting its commercial applications.Here,we propose a multilevel carbon architecture with vertical graphene sheets(VGSs)grown on surfaces of subnanoscopically and homogeneously dispersed Si–C composite nanospheres,which are subsequently embedded into a carbon matrix(C/VGSs@Si–C).Subnanoscopic C in the Si–C nanospheres,VGSs,and carbon matrix form a three‐dimensional conductive and robust network,which significantly improves the conductivity and suppresses the volume expansion of Si,thereby boosting charge transport and improving electrode stability.The VGSs with vast exposed edges considerably increase the contact area with the carbon matrix and supply directional transport channels through the entire material,which boosts charge transport.The carbon matrix encapsulates VGSs@Si–C to decrease the specific surface area and increase tap density,thus yielding high first Coulombic efficiency and electrode compaction density.Consequently,C/VGSs@Si–C delivers excellent Li‐ion storage performances under industrial electrode conditions.In particular,the full cells show high energy densities of 603.5 Wh kg^(−1)and 1685.5 Wh L^(−1)at 0.1 C and maintain 80.7%of the energy density at 3 C. 展开更多
关键词 fast charging high energy densities lithium‐ion batteries multilevel carbon architecture subnanoscopic silicon anode
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11.2 W/mm power density AlGaN/GaN high electron-mobility transistors on a GaN substrate 被引量:1
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作者 Yansheng Hu Yuangang Wang +11 位作者 Wei Wang Yuanjie Lv Hongyu Guo Zhirong Zhang Hao Yu Xubo Song Xingye zhou Tingting Han Shaobo Dun Hongyu Liu Aimin Bu Zhihong Feng 《Journal of Semiconductors》 EI CAS CSCD 2024年第1期38-41,共4页
In this letter,high power density AlGaN/GaN high electron-mobility transistors(HEMTs)on a freestanding GaN substrate are reported.An asymmetricΓ-shaped 500-nm gate with a field plate of 650 nm is introduced to improv... In this letter,high power density AlGaN/GaN high electron-mobility transistors(HEMTs)on a freestanding GaN substrate are reported.An asymmetricΓ-shaped 500-nm gate with a field plate of 650 nm is introduced to improve microwave power performance.The breakdown voltage(BV)is increased to more than 200 V for the fabricated device with gate-to-source and gate-to-drain distances of 1.08 and 2.92μm.A record continuous-wave power density of 11.2 W/mm@10 GHz is realized with a drain bias of 70 V.The maximum oscillation frequency(f_(max))and unity current gain cut-off frequency(f_(t))of the AlGaN/GaN HEMTs exceed 30 and 20 GHz,respectively.The results demonstrate the potential of AlGaN/GaN HEMTs on freestanding GaN substrates for microwave power applications. 展开更多
关键词 freestanding GaN substrates AlGaN/GaN HEMTs continuous-wave power density breakdown voltage Γ-shaped gate
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Anisotropic Band Evolution of Bulk Black Phosphorus Induced by Uniaxial Tensile Strain
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作者 邓亚丰 张艺琳 +7 位作者 赵亚飞 徐永康 代兴泽 王双海 陆显扬 黎遥 徐永兵 何亮 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第3期83-96,共14页
We investigate the anisotropic band structure and its evolution under tensile strains along different crystallographic directions in bulk black phosphorus(BP)using angle-resolved photoemission spectroscopy and density... We investigate the anisotropic band structure and its evolution under tensile strains along different crystallographic directions in bulk black phosphorus(BP)using angle-resolved photoemission spectroscopy and density functional theory.The results show that there are band crossings in the Z-L(armchair)direction. 展开更多
关键词 DIRECTIONS bulk PHOSPHORUS
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“Glass-quake”in elastically loaded bulk metallic glasses
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作者 Qi Huang Kaiguo Chen +7 位作者 Chen Liu Guisen Liu Yang Shao Chenlong Zhao Ran Chen Hengtong Bu Lingti Kong Yao Shen 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第11期367-371,共5页
Amorphous solids exhibit scale-free avalanches,even under small external loading,and thus can work as suitable systems to study critical behavior and universality classes.The abundance of scale-free avalanches in the ... Amorphous solids exhibit scale-free avalanches,even under small external loading,and thus can work as suitable systems to study critical behavior and universality classes.The abundance of scale-free avalanches in the entire elastic tension regime of bulk metallic glass(BMG)samples has been experimentally observed using acoustic emission(AE)measurements.In this work,we compare the statistics of avalanches with those of earthquakes,and find that they both follow the Gutenberg–Richter law in the statistics of energies and Omori’s law of aftershock rates,and share the same characteristics in the distribution of recurrence times.These resemblances encourage us to propose the term“glass-quake”to describe avalanches in elastically loaded BMGs.Furthermore,our work echoes the potential universality of critical behavior in disordered physical systems from atomic to planetary scales,and motivates the use of elastic loaded BMGs as valuable laboratory simulators of seismic dynamics. 展开更多
关键词 bulk metallic glass AVALANCHE EARTHQUAKE disorder system time series
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Bulk geochemistry,Rb-Sr,Sm-Nd,and stable O-H isotope systematics of the Metzimevin high-grade iron ore deposit,Mbalam iron ore district,southern Cameroon
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作者 Samndong Cyril Tufoin Cheo Emmanuel Suh +1 位作者 Tabod Charles Tabod George Lemewihbwen Ngiamte 《Acta Geochimica》 EI CAS CSCD 2024年第4期677-706,共30页
Bulk geochemistry,Sr,Nd,and O-H isotope systematics are reported for the first time on banded iron formation(BIF)-hosted high-grade iron ore at the northwestern segment of Congo Craton(CC).Located in Mbalam iron ore d... Bulk geochemistry,Sr,Nd,and O-H isotope systematics are reported for the first time on banded iron formation(BIF)-hosted high-grade iron ore at the northwestern segment of Congo Craton(CC).Located in Mbalam iron ore district,Southern Cameroon,Metzimevin iron ore deposit is a hematite-magnetite BIF system,dominated by SiO_(2)+Fe_(2)O_(3)(97.1 to 99.84 wt%),with low concentrations of clastic elements e.g.,Al_(2)O_(3),TiO_(2),and HFSE,depicting a nearly pure chemical precipitate.The REE+Y signature of the iron deposit displays strong positive Eu anomaly,strong negative Ce anomaly,and chondritic to superchondritic Y/Ho ratios,suggestive of formation by mixed seawater-high temperature hydrothermal fluids in oxidising environment.The^(87)Sr/^(86)Sr ratios of the BIF are higher than the maximum^(87)Sr/^(86)Sr evolution curves for all Archean reservoirs(bulk silicate earth,Archean crust and Archean seawater),indicating involvement of continentally-derived components during BIF formation and alteration.TheƐ_(Nd)(t)(+2.26 to+3.77)and Nd model age indicate that chemical constituents for the BIF were derived from undifferentiated crustal source,between 3.002 and 2.88 Ga.The variable and diverse O and H isotope data(−1.9‰to 17.3‰and−57‰to 136‰respectively)indicate that the Metzimevin iron ore formed initially from magmatic plumes and later enriched by magmatic-metamorphic-modified meteoric fluids.Mass balance calculations indicate mineralisation by combined leaching and precipitation,with an average iron enrichment factor of>2.67 and SiO_(2)depletion factor of>0.99.This is associated with an overall volume reduction of 28.27%,reflecting net leaching and volume collapse of the BIF protholith. 展开更多
关键词 bulk geochemistry RB-SR SM-ND Mitzimevin High-grade iron ore
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A bulk extraction method to determine the stable isotope ratios of iron,nickel,copper,zinc,and cadmium in seawater using multi-collector inductively coupled plasma mass spectrometry
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作者 Zhan Shen Yuncong Ge +3 位作者 Jiahui Liu Wenkai Guan Wenfeng Hu Ruifeng Zhang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第7期125-137,共13页
The oceanic trace metals iron(Fe),nickel(Ni),copper(Cu),zinc(Zn),and cadmium(Cd)are crucial to marine phytoplankton growth and global carbon cycle,and the analysis of their stable isotopes can provide valuable insight... The oceanic trace metals iron(Fe),nickel(Ni),copper(Cu),zinc(Zn),and cadmium(Cd)are crucial to marine phytoplankton growth and global carbon cycle,and the analysis of their stable isotopes can provide valuable insights into their biogeochemical cycles within the ocean.However,the simultaneous isotopic analysis of multiple elements present in seawater is challenging because of their low concentrations,limited volumes of the test samples,and high salt matrix.In this study,we present the novel method developed for the simultaneous analysis of five isotope systems by 1 L seawater sample.In the developed method,the NOBIAS Chelate-PA1 resin was used to extract metals from seawater,the AG MP-1M anion-exchange resin to purify Cu,Fe,Zn,Cd,and the NOBIAS Chelate-PA1 resin to further extract Ni from the matrix elements.Finally,a multi-collector inductively coupled plasma mass spectroscope(MC-ICPMS)was employed for the isotopic measurements using a doublespike technique or sample-standard bracketing combined with internal normalization.This method exhibited low total procedural blanks(0.04 pg,0.04 pg,0.21 pg,0.15 pg,and 3 pg for Ni,Cu,Fe,Zn,and Cd,respectively)and high extraction efficiencies(100.5%±0.3%,100.2%±0.5%,97.8%±1.4%,99.9%±0.8%,and 100.1%±0.2%for Ni,Cu,Fe,Zn,and Cd,respectively).The external errors and external precisions of this method could be considered negligible.The proposed method was further tested on the seawater samples obtained from the whole vertical profile of a water column during the Chinese GEOTRACES GP09 cruise in the Northwest Pacific,and the results showed good agreement with previous related data.This innovative method will contribute to the advancement of isotope research and enhance our understanding of the marine biogeochemical cycling of Fe,Ni,Cu,Zn,and Cd. 展开更多
关键词 trace metal stable isotopes seawater bulk extraction
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单细胞测序与Bulk RNA测序联合分析构建膀胱癌风险预后模型
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作者 李自智 李俊义 +1 位作者 曹庆飞 佟明 《锦州医科大学学报》 CAS 2024年第2期30-39,共10页
目的本研究致力于开发一种基于膀胱癌核心细胞差异性表达基因的预后风险评估模型。通过在多个数据集中验证其效力,旨在为膀胱癌患者提供一个新的临床应用工具,用于预后风险评估。方法本研究综合利用了单细胞和Bulk RNA测序数据。我们首... 目的本研究致力于开发一种基于膀胱癌核心细胞差异性表达基因的预后风险评估模型。通过在多个数据集中验证其效力,旨在为膀胱癌患者提供一个新的临床应用工具,用于预后风险评估。方法本研究综合利用了单细胞和Bulk RNA测序数据。我们首先从GEO数据库下载并分析了相关的膀胱癌单细胞和芯片RNA数据集。通过生物信息学方法,我们鉴定了核心细胞的差异性表达基因,并对其进行了功能及通路富集分析。基于这些分析,我们使用单变量和多变量Cox回归方法筛选出与膀胱癌预后显著相关的关键基因,并据此构建了一个预后风险评估模型。该模型在TCGA-BLCA数据集中进一步进行了效力验证。结果经过全面的生物信息学分析,我们鉴定出了223个核心细胞的差异性表达基因。这些基因在细胞外基质的结构和功能方面发挥着重要作用。构建的预后风险评估模型包括5个独立的预后相关基因(MFAP5、PDE4D、ISG15、ADAMTS1和FGL2)。在GEO和TCGA-BLCA数据集中的验证结果表明,该模型具有良好的预测效力,为膀胱癌患者的预后评估提供新型生物学标志工具。结论本研究成功开发了一个基于5个关键基因标志物的膀胱癌预后风险评估模型并具有良好的预测效力。此模型的开发为膀胱癌的生物学研究和临床预后评估提供了一个新的工具,有助于更好地理解膀胱癌的生物学特性并指导患者的个性化治疗。 展开更多
关键词 膀胱癌 单细胞RNA测序 bulk RNA测序 预后风险评估模型 生物信息学分析
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Thermodynamics-directed bulk/grain-boundary engineering for superior electrochemical durability of Ni-rich cathode
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作者 Kangyu Zou Mingzhu jiang +5 位作者 Tianxiang Ning Lei Tan Junchao Zheng Jiexi Wang Xiaobo Ji Lingjun Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第10期321-331,I0006,共12页
Introducing high-valence Ta element is an essential strategy for addressing the structu ral deterioration of the Ni-rich LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM)cathode,but the enlarged Li/Ni cation mixing leads to the infe... Introducing high-valence Ta element is an essential strategy for addressing the structu ral deterioration of the Ni-rich LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM)cathode,but the enlarged Li/Ni cation mixing leads to the inferior rate capability originating from the hindered Li~+migration.Note that the non-magnetic Ti~(4+)ion can suppress Li/Ni disorder by removing the magnetic frustration in the transition metal layer.However,it is still challenging to directionally design expected Ta/Ti dual-modification,resulting from the complexity of the elemental distribution and the uncertainty of in-situ formed coating compounds by introducing foreign elements.Herein,a LiTaO_3 grain boundary(GB)coating and bulk Ti-doping have been successfully achieved in LiNi_(0.834)Co_(0.11)Mn_(0.056)O_(2) cathode by thermodynamic guidance,in which the structural formation energy and interfacial binding energy are employed to predict the elemental diffusion discrepancy and thermodynamically stable coating compounds.Thanks to the coupling effect of strengthened structural/interfacial stability and improved Li~+diffusion kinetics by simultaneous bulk/GB engineering,the Ta/Ti-NCM cathode exhibits outstanding capacity retention,reaching 91.1%after 400 cycles at 1 C.This elaborate work contributes valuable insights into rational dual-modification engineering from a thermodynamic perspective for maximizing the electrochemical performances of NCM cathodes. 展开更多
关键词 Ni-rich layered cathode Dual-modification Grain boundary coating bulk doping Thermodynamic perspective
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Understanding the correlation between energy-state mismatching and open-circuit voltage loss in bulk heterojunction solar cells
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作者 Hyun-Seock Yang Danbi Kim +7 位作者 Chang-Mok Oh Vellaiappillai Tamilavan Pesi MHangoma Hojun Yi Bo RLee Insoo Shin In-Wook Hwang Sung Heum Park 《Carbon Energy》 SCIE EI CAS CSCD 2024年第5期164-174,共11页
Photoinduced intermolecular charge transfer(PICT)determines the voltage loss in bulk heterojunction(BHJ)organic photovoltaics(OPVs),and this voltage loss can be minimized by inducing efficient PICT,which requires ener... Photoinduced intermolecular charge transfer(PICT)determines the voltage loss in bulk heterojunction(BHJ)organic photovoltaics(OPVs),and this voltage loss can be minimized by inducing efficient PICT,which requires energy-state matching between the donor and acceptor at the BHJ interfaces.Thus,both geometrically and energetically accessible delocalized state matching at the hot energy level is crucial for achieving efficient PICT.In this study,an effective method for quantifying the hot state matching of OPVs was developed.The degree of energy-state matching between the electron donor and acceptor at BHJ interfaces was quantified using a mismatching factor(MF)calculated from the modified optical density of the BHJ.Furthermore,the correlation between the open-circuit voltage(Voc)of the OPV device and energy-state matching at the BHJ interface was investigated using the calculated MF.The OPVs with small absolute MF values exhibited high Voc values.This result clearly indicates that the energy-state matching between the donor and acceptor is crucial for achieving a high Voc in OPVs.Because the MF indicates the degree of energy-state matching,which is a critical factor for suppressing energy loss,it can be used to estimate the Voc loss in OPVs. 展开更多
关键词 bulk heterojunction open circuit voltage organic photovoltaics photoinduced charge transfer voltage loss
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Electron density measurement by the three boundary channels of HCOOH laser interferometer on the HL-3 tokamak
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作者 牟俊任 李永高 +5 位作者 李远 王再宏 丁宝钢 王浩西 易江 石中兵 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第3期88-93,共6页
Far-infrared(FIR)interferometer is widely used to measure the electron density in the magnetically confined fusion plasma devices.A new FIR laser interferometer with a total of 13 channels(8 horizontal channels and 5 ... Far-infrared(FIR)interferometer is widely used to measure the electron density in the magnetically confined fusion plasma devices.A new FIR laser interferometer with a total of 13 channels(8 horizontal channels and 5 oblique channels)is under development on the HL-3tokamak by using the formic-acid laser(HCOOH,f=694 GHz).In order to investigate the boundary electron density activity during the divertor discharge,three horizontal interferometry channels located at Z=-97,-76,76.5 cm have been successfully developed on HL-3 in 2023,and put into operation in recent experimental campaign,with a time resolution of<1.0μs and lineintegrated electron density resolution of~7.0×10^(16) m^(-2).This paper mainly focuses on the optical design of the three-channel interferometry system,as well as optical elements and recent experimental result on HL-3. 展开更多
关键词 electron density INTERFEROMETER HL-3
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Comparison of a Spectral Bin and Two Multi-Moment Bulk Microphysics Schemes for Supercell Simulation:Investigation into Key Processes Responsible for Hydrometeor Distributions and Precipitation
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作者 Marcus JOHNSON Ming XUE Youngsun JUNG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第5期784-800,共17页
There are more uncertainties with ice hydrometeor representations and related processes than liquid hydrometeors within microphysics parameterization(MP)schemes because of their complicated geometries and physical pro... There are more uncertainties with ice hydrometeor representations and related processes than liquid hydrometeors within microphysics parameterization(MP)schemes because of their complicated geometries and physical properties.Idealized supercell simulations are produced using the WRF model coupled with“full”Hebrew University spectral bin MP(HU-SBM),and NSSL and Thompson bulk MP(BMP)schemes.HU-SBM downdrafts are typically weaker than those of the NSSL and Thompson simulations,accompanied by less rain evaporation.HU-SBM produces more cloud ice(plates),graupel,and hail than the BMPs,yet precipitates less at the surface.The limiting mass bins(and subsequently,particle size)of rimed ice in HU-SBM and slower rimed ice fall speeds lead to smaller melting-level net rimed ice fluxes than those of the BMPs.Aggregation from plates in HU-SBM,together with snow–graupel collisions,leads to a greater snow contribution to rain than those of the BMPs.Replacing HU-SBM’s fall speeds using the formulations of the BMPs after aggregating the discrete bin values to mass mixing ratios and total number concentrations increases net rain and rimed ice fluxes.Still,they are smaller in magnitude than bulk rain,NSSL hail,and Thompson graupel net fluxes near the surface.Conversely,the melting-layer net rimed ice fluxes are reduced when the fall speeds for the NSSL and Thompson simulations are calculated using HU-SBM fall speed formulations after discretizing the bulk particle size distributions(PSDs)into spectral bins.The results highlight precipitation sensitivity to storm dynamics,fall speed,hydrometeor evolution governed by process rates,and MP PSD design. 展开更多
关键词 PRECIPITATION spectral bin microphysics bulk microphysics parameterization microphysics processes WRF model supercell storm
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