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SiC Lateral Devices on Semi-insulating Substrate
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作者 Chih-Fang Huang 《电力电子技术》 CSCD 北大核心 2017年第8期17-19,共3页
The advancements in the technology development for silicon carbide(SiC) lateral devices are summarized in the past years.By replacing conducting substrates in the conventional devices with semi-insulating ones and by ... The advancements in the technology development for silicon carbide(SiC) lateral devices are summarized in the past years.By replacing conducting substrates in the conventional devices with semi-insulating ones and by considering the charge compensation in the drift layer based on superjunction principle, blocking voltage can be enhanced by more than two times compared with those values reported in the literature.SiC lateral PiN diodes,JFETs,MOSFETs and IGBTs are realized with blocking voltages as high as 4.2 kV.A COMS inverter is also demonstrated at the sametime with the process of high-voltage lateral IGBTs, showing the potential for future SiC power management integrated circuits(ICs). 展开更多
关键词 碳化硅 技术创新 电荷补偿 阻断电压
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8-inch free-standing GaN substrates grown by hydride vapor phase epitaxy
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作者 Ruihua Zhang Fang Liu +12 位作者 Yao Wu Hongfen Xu Jinmi He Ming Liu Jianhui Wang Kunyang Li Ping Wang Jiejun Wu Tongjun Yu Qi Wang Jingquan Lu Guoyi Zhang Xinqiang Wang 《Journal of Semiconductors》 2026年第2期80-86,共7页
The absence of large-size gallium nitride(GaN) substrates with low dislocation density remains a primary bottleneck for advancing GaN-based devices. Here, we demonstrate the achievement of 8-inch freestanding GaN subs... The absence of large-size gallium nitride(GaN) substrates with low dislocation density remains a primary bottleneck for advancing GaN-based devices. Here, we demonstrate the achievement of 8-inch freestanding GaN substrates grown by hydride vapor phase epitaxy. Critical to this achievement is the improvement in gas-flow uniformity, which ensures exceptional thickness homogeneity and enables the crack-free growth of GaN. After laser lift-off(LLO) separation, the freestanding GaN substrate exhibits superior crystal quality, evidenced by full width at half maximum values of 68 and 54 arcsec for X-ray diffraction rocking curves of(002) and(102) planes, alongside a low dislocation density of 1.6 × 10^(6) cm^(-2). This approach establishes a robust pathway for the production of large-size GaN substrates, which are essential for advancing next-generation power electronics and high-efficiency photonics. 展开更多
关键词 gallium nitride single-crystal substrates large size hydride vapor phase epitaxy
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NAD substrate deficiency is an inherent and targetable risk factor for late-onset Alzheimer’s disease
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作者 Kai-Christian Sonntag Bruce M.Cohen 《Neural Regeneration Research》 2026年第6期2331-2332,共2页
Sporadic or late-onset Alzheimer’s disease(LOAD)occurs in 1 of 10 people over 65 years of age and comprises 95%of all AD patients.Unlike early-onset AD,which is caused by defined single gene mutations,the mechanisms ... Sporadic or late-onset Alzheimer’s disease(LOAD)occurs in 1 of 10 people over 65 years of age and comprises 95%of all AD patients.Unlike early-onset AD,which is caused by defined single gene mutations,the mechanisms and events underlying risk for LOAD are not fully understood and no substantial disease-modifying interventions are currently available.Age is the most prominent risk factor for LOAD,and interacting age-related and LOAD-associated factors contribute to its pathogenesis.Among these factors are changes in bioenergetic cell functions,which metabolize substrates and produce energy stored in adenosine triphosphate. 展开更多
关键词 substrate deficiency load adenosine triphosphate bioenergetic cell functions late onset Alzheimers disease
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Optimal combination of substrate supply amount coupled with nutrient solution management program for cucumber planting
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作者 Zhen Kang Zhaoxi Jiang +5 位作者 Zhaolong Liu Peng Wang Caihong Zhang Maozhou Yuan Mengqi Bai Xiaohui Hu 《Horticultural Plant Journal》 2026年第1期136-148,共13页
Substrate and nutrient supply are essential for vegetable cultivation in greenhouse.The strategies for plant nutrient supply vary depending on the cultivation methods or substrate dosages employed.With the development... Substrate and nutrient supply are essential for vegetable cultivation in greenhouse.The strategies for plant nutrient supply vary depending on the cultivation methods or substrate dosages employed.With the development of mechanization,wide-row spacing substrate cultivation became an optimize mode of the greenhouse cucumber cultivation,aligning with the trend of intelligent agriculture.To determine the optimal nutrient solution supply amount(NS)and supply frequency(SF)for promoting the integrated growth of cucumber under wide-row spacing substrate cultivation,we explored the effects of substrate supply amount(SS),NS,and SF on cucumber yield,quality,and element utilization efficiency.A five-level quadratic orthogonal rotation combination design with three experimental factors(NS,SF,and SS)was implemented for 23 coupling treatments over three growing seasons,including spring(2022S and 2023S)and autumn(2022A).The technique for order preference by similarity to ideal solution(TOPSIS)combining weights based on game theory was applied to construct cucumber comprehensive growth evaluation model.Single and two experimental factors analyses revealed significant effects of single factors and the coupling of NS-SS,NS-SF and SS-SF on the integrated growth of cucumber for all three growing seasons.For the NS-SF-SS combination,the optimal parameters for comprehensive cucumber growth were determined as follows:levels of^(-1).68 for NS,-0.7 for SF,and^(-1).682 for SS in 2022A;-0.43 for NS,-0.06 for SF,and 0.34 for SS in 2022S;0.3 for NS,-0.02 for SF,and 0.04 for SS in 2023S.Furthermore,for SS ranges of 2.00-3.01,3.01-4.50,4.50-5.99,5.99-7.00(L·plant^(-1)),the corresponding NS and SF intervals maximizing cucumber integrated growth in spring were:0.28-0.30(L·plant^(-1))and 6(times·d^(-1)),0.26-0.30(L·plant^(-1))and 6(times·d^(-1)),0.25-0.30(L·plant^(-1))and 6(times·d^(-1)),0.23-0.30(L·plant^(-1))and 6(times·d^(-1)),respectively.With the same SS,the corresponding NS and SF intervals that maximized cucumber integrated growth in autumn were:0.10(L·plant^(-1))and 8(times·d^(-1)),0.18(L·plant^(-1))and 7(times·d^(-1)),0.30(L·plant^(-1))and 6(times·d^(-1)),0.49(L·plant^(-1))and 5(times·d^(-1)),respectively.The results provide a theoretical basis for solution management,and further in-depth research on cucumber cultivation. 展开更多
关键词 Cucumis sativus L. Comprehensive growth Irrigation frequency Nutrient solution substrate supply amount Wide row spacing
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Fabrication and characterization of one-port surface acoustic wave resonators on semi-insulating GaN substrates 被引量:5
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作者 Xue Ji Wen-Xiu Dong +2 位作者 Yu-Min Zhang Jian-Feng Wang Ke Xu 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第6期414-418,共5页
One-port surface acoustic wave resonators(SAWRs) are fabricated on semi-insulating high-quality bulk GaN and GaN film substrates, respectively. The semi-insulating GaN substrates are grown by hydride vapor phase epita... One-port surface acoustic wave resonators(SAWRs) are fabricated on semi-insulating high-quality bulk GaN and GaN film substrates, respectively. The semi-insulating GaN substrates are grown by hydride vapor phase epitaxy(HVPE)and doped with Fe. The anisotropy of Rayleigh propagation and the electromechanical coupling coefficient in Fe-doped GaN are investigated. The difference in resonance frequency between the SAWs between [1120] GaN and [1100] GaN is about 0.25% for the Rayleigh propagation mode, which is smaller than that of non-intentionally doped GaN film(~1%)reported in the literature. The electromechanical coupling coefficient of Fe-doped GaN is about 3.03%, which is higher than that of non-intentionally doped GaN film. The one-port SAWR fabricated on an 8-μm Fe-doped GaN/sapphire substrate has a quality factor of 2050, and that fabricated on Fe-doped bulk GaN has a quality factor as high as 3650. All of our results indicate that high-quality bulk GaN is a very promising material for application in SAW devices. 展开更多
关键词 surface acoustic wave one-port resonator GALLIUM nitride(GaN) semi-insulating FE-DOPED
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High-Performance In0.23Ga0.77As Channel MOSFETs with High Current Ratio Ion/Ioff Grown on Semi-insulating GaAs Substrates by MOCVD
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作者 孔祥挺 周旭亮 +4 位作者 李士颜 乔丽君 刘洪刚 王圩 潘教青 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第3期121-123,共3页
We demonstrate high-performance In0.23 Ga0.77 As channel metal-oxide-semiconductor field-effect transistors ( MOS- FETs) with high on-current to off-current (Ion/Ioff) ratio grown on semi-insulating GaAs wafers by... We demonstrate high-performance In0.23 Ga0.77 As channel metal-oxide-semiconductor field-effect transistors ( MOS- FETs) with high on-current to off-current (Ion/Ioff) ratio grown on semi-insulating GaAs wafers by metal-organic chemical vapor deposition (MOCVD). The 2μm channel-length devices exhibit a peak extrinsic transeonductance of 150 mS/mm and a drain current up to 500 mA/mm. The maximum effective mobility is 1680 cm2/Vs extracted by the split C-V method. Furthermore, the Ion/Ioff ratio is significantly improved from approximately 4.5 × 10^3 up to approximately 4.32 × 10^4 by controlling the etch thickness of In0.49Ga0.51P, The high drain current and high Ion/Ioff ratio of the In0.23Ga0.77As channel MOSFETs are achieved due to the high effective mobility and the low gate leakage current density. 展开更多
关键词 As Channel MOSFETs with High Current Ratio I MOSFET Ga Grown on semi-insulating GaAs substrates by MOCVD off
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Backgating effect in GaAs FETs with a channel–semi-insulating substrate boundary 被引量:1
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作者 Ahmed Chaouki Megherbi Said Benramache Abderrazak Guettaf 《Journal of Semiconductors》 EI CAS CSCD 2014年第3期33-38,共6页
This study focuses on modeling the effects of deep hole traps, mainly the effect of the substrate(backgating effect) in a GaAs transistor MESFT. This effect is explained by the existence, at the interface, of a spac... This study focuses on modeling the effects of deep hole traps, mainly the effect of the substrate(backgating effect) in a GaAs transistor MESFT. This effect is explained by the existence, at the interface, of a space charge zone. Any modulation in this area leads to response levels trapping the holes therein to the operating temperature. We subsequently developed a model treating the channel substrate interface as an N–P junction, allowing us to deduce the time dependence of the component parameters of the total resistance R ds, the pinch-off voltage V P, channel resistance, fully open R co and the parasitic series resistance R S to bind the effect trap holes H1and H0. When compared with the experimental results, the values of the R DS(t S/ model for both traps show that there is an agreement between theory and experiment; it has inferred parameter traps, namely the density and the time constant of the trap. This means that a space charge region exists at the channel–substrate interface and that the properties can be approximated to an N–P junction. 展开更多
关键词 traps pinch-off voltage resistance channel substrate interface
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Effects of biomass co-pyrolysis and herbaceous plant colonization on the transformation of tailings into soil like substrate 被引量:1
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作者 Bin Zhu Meiyan Si +4 位作者 Xin Xie Ximin Yan Jianhong Huang Senlin Tian Ping Ning 《Journal of Environmental Sciences》 2025年第1期230-243,共14页
Enhancing soil organic matter characteristics,ameliorating physical structure,mitigating heavy metal toxicity,and hastening mineral weathering processes are crucial approaches to accomplish the transition of tailings ... Enhancing soil organic matter characteristics,ameliorating physical structure,mitigating heavy metal toxicity,and hastening mineral weathering processes are crucial approaches to accomplish the transition of tailings substrate to a soil-like substrate.The incorporation of biomass co-pyrolysis and plant colonization has been established to be a significant factor in soil substrate formation and soil pollutant remediation.Despite this,there is presently an absence of research efforts aimed at synergistically utilizing these two technologies to expedite the process of mining tailings soil substrate formation.The current study aimed to investigate the underlying mechanism of geochemical changes and rapid mineral weathering during the process of transforming tailings substrate into a soil-like substrate,under the combined effects of biomass co-smoldering pyrolysis and plant colonization.The findings of this study suggest that the incorporation of smoldering pyrolysis and plant colonization induces a high-temperature effect and biological effects,which enhance the physical and chemical properties of tailings,while simultaneously accelerating the rate of mineral weathering.Notable improvements include the amelioration of extreme pH levels,nutrient enrichment,the formation of aggregates,and an increase in enzyme activity,all of which collectively demonstrate the successful attainment of tailings substrate reconstruction.Evidence of the acceleratedweathering was verified by phase and surfacemorphology analysis using X-ray diffraction and scanning electron microscopy.Discovered corrosion and fragmentation on the surface ofminerals.The weathering resulted in corrosion and fragmentation of the surface of the treated mineral.This study confirms that co-smoldering pyrolysis of biomass,combined with plant colonization,can effectively promote the transformation of tailings into soil-like substrates.This method has can effectively address the key challenges that have previously hindered sustainable development of the mining industry and provides a novel approach for ecological restoration of tailings deposits. 展开更多
关键词 SMOLDERING Biomass co-pyrolysis Phytoremediation Soil-like substrate Tailing restoration
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Inhibition of jarosite heterogeneous crystallization on anglesite via in-situ formation of competitive substrate 被引量:1
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作者 Jiahui Wu Xu Yan +6 位作者 Feiping Zhao Yong Ke Haiying Wang Wenchao Zhang Qingwei Wang Meiqing Shi Liyuan Chai 《Journal of Environmental Sciences》 2025年第3期394-405,共12页
Heterogeneous crystallization is a common occurrence during the formation of solidwastes.It leads to the encapsulation of valuable/hazardous metals within the primary phase,presenting significant challenges for waste ... Heterogeneous crystallization is a common occurrence during the formation of solidwastes.It leads to the encapsulation of valuable/hazardous metals within the primary phase,presenting significant challenges for waste treatment andmetal recovery.Herein,we proposed a novel method involving the in-situ formation of a competitive substrate during the precipitation of jarosite waste,which is an essential process for removing iron in zinc hydrometallurgy.We observed that the in-situ-formed competitive substrate effectively inhibits the heterogeneous crystallization of jarosite on the surface of anglesite,a lead-rich phase present in the jarositewaste.As a result,the iron content on the anglesite surface decreases from34.8%to 1.65%.The competitive substrate was identified as schwertmannite,characterized by its loose structure and large surface area.Furthermore,we have elucidated a novel mechanism underlying this inhibition of heterogeneous crystallization,which involves the local supersaturation of jarosite caused by the release of ferric and sulfate ions from the competitive substrate.The local supersaturation promotes the preferential heterogeneous crystallization of jarosite on the competitive substrate.Interestingly,during the formation of jarosite,the competitive substrate gradually vanished through a dissolution-recrystallization process following the Ostwald rule,where a metastable phase slowly transitions to a stable phase.This effectively precluded the introduction of impurities and reduced waste volume.The goal of this study is to provide fresh insights into the mechanism of heterogeneous crystallization control,and to offer practical crystallization strategies conducive to metal separation and recovery from solid waste in industries. 展开更多
关键词 Heterogeneous crystallization Jarosite waste Competitive substrate Zinc hydrometallurgy
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Optimizing the Particle Size of Shale and Laterite Used as Constructed Wetland Substrates for Wastewater Treatment
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作者 Nadège Fatim Traoré Jean-Marie Pétémanagnan Ouattara +2 位作者 Franck Michaël Zahui Amichalé Jean Cyrille Beda Aman Messou 《Journal of Water Resource and Protection》 2025年第1期14-34,共21页
Constructed Wetlands (CWs) are currently one of the most promising techniques for wastewater treatment, having demonstrated their effectiveness. However, the choice of substrate particle size is critical to the smooth... Constructed Wetlands (CWs) are currently one of the most promising techniques for wastewater treatment, having demonstrated their effectiveness. However, the choice of substrate particle size is critical to the smooth operation of the process, as hydrodynamic constraints require a coarse particle size, whereas wastewater treatment recommends a fine particle size. This study investigates the suitability of laterite and shale as substrates of different sizes (1 - 3, 3 - 5 and 5 - 8 mm) in CWs for domestic wastewater treatment. The study was carried out in an experimental pilot plant consisting of 12 parallelepiped beds (C × C = 0.4 × 0.4 m2;H = 0.6 m) filled from bottom to top with 0.1 m of gravel and 0.4 m of shale or laterite of different grain sizes with two replications. During the six months of operation, plant biomass and stem diameter of Pennisetum purpureum used as vegetation in the CWs were determined. Raw and treated water were also sampled and analyzed for pollutants, including chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total Kjedahl nitrogen (TKN), total phosphorus (TP), and total suspended solids (TSS), using International Organization for Standardization (ISO) analytical methods. P. purpureum developed much better in the CW beds lined with shale;plant biomass ranged from 13.8 to 14.7 kg/m2 and from 11.2 to 12.5 kg/m2 in the beds lined with shale and laterite, respectively, as did stump diameter, which ranged from 15.5 to 16.1 cm and from 11.10 to 12.7 cm, respectively. However, the highest values for biomass and stump diameter for each material were obtained in the beds lined with 1 - 3 mm geomaterials. Pollutant removal efficiencies were highest in the CWs lined with laterite and shale of 1 - 3 mm grain size (76.9% - 83% COD, 78% - 84.7% BOD5, 55.5% - 72.2% TKN, 58.4% - 72.4% TP, 78.1% - 80.2% TSS), with the highest values recorded in the shale-lined beds. However, the 3 - 5 mm grain size of both materials provided quality filtrates (140 - 174 mg/L COD, 78.5 - 94.8 mg/L BOD5, 4.6 - 5.7 mg/L TP) in line with local wastewater discharge levels. This size of geomaterials appears to be suitable for optimization purposes, although further work with these materials, such as increasing the depth of the wetland, is required to improve the level of NTK and TSS discharge. 展开更多
关键词 Constructed Wetlands Domestic Wastewater LATERITE Pennisetum purpureum SHALE substrate Grain Size
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Elucidating the Substrate Specificity of Cytochrome P450 Enzymes:Insights into N-and S-Containing Small-Molecule Metabolism
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作者 Chaohua Yan Guilin Wei +4 位作者 Zhuoan Jin Xiaodong Li Liuyi Yang Liwei Zou Ling Yang 《Engineering》 2025年第11期229-250,共22页
Cytochrome P450 enzymes(P450s or CYPs)are the primary metabolic contributors to the absorption,distribution,metabolism,and excretion(ADME)properties of small-molecule drugs.These enzymes can catalyze various types of ... Cytochrome P450 enzymes(P450s or CYPs)are the primary metabolic contributors to the absorption,distribution,metabolism,and excretion(ADME)properties of small-molecule drugs.These enzymes can catalyze various types of reactions,including metabolic reactions that occur at nitrogen(N)and sulfur(S)sites of small molecules.In this review,we conducted a comprehensive statistical analysis of 294 P450s-mediated small-molecule substrates,among which more than 47%substrates contained N and S.The purpose of the analysis is to elucidate the broad-spectrum cross-reactivity and specificity between these substrates and various CYP isoforms across five reaction types.Our findings reveal that substrates with molecular weights greater than 500 Da or less than 200 Da are predominantly governed by the dominant effect of the CYP isoform’s active sites.In contrast,small-to medium-sized molecules with molecular weights ranging from 200 to 400 Da exhibit a stronger dependence on the types of heteroatoms they contain,with the size of the enzyme’s catalytic site(cavity)playing a negligible role in determining substrate specificity.This review starts from the metabolic mechanisms of P450s-mediated N-and S-containing compounds,and systematically analyzes the structural characteristics of substrates involved in N-dealkylation,N-oxidation,and S-oxidation,as well as their metabolic interactions with P450s.These analyses provide a new perspective for improving the existing understanding of the relationship between the P450s substrate specificity and substrate structural characteristics,and offer a valuable perspective for enhancing drug design and predicting metabolic stability based on the P450s-catalyzed reaction framework. 展开更多
关键词 Drug metabolism Cytochrome P450 enzymes Active sites/catalytic sites substrate specificity N-and S-containing substrates
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Nanosizing enhancement of hydrogen storage performance and mechanism in Mg-based materials:Nano-substrate modulation,nano-catalyst construction,and nano-catalytic mechanisms
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作者 Duode Zhao Xiaojiang Hou +8 位作者 Yu Ge Dongfeng Sun Danting Li Chenlu Wang Xinlei Xie Peixuan Zhu Xiaohui Ye Guoquan Suo Yanling Yang 《Journal of Energy Chemistry》 2025年第10期609-636,共28页
The magnesium-based materials are acknowledged as one of the most promising solid-state hydrogen storage mediums,attributed to their superior hydrogen storage capacity.Nevertheless,challenges such as sluggish kinetics... The magnesium-based materials are acknowledged as one of the most promising solid-state hydrogen storage mediums,attributed to their superior hydrogen storage capacity.Nevertheless,challenges such as sluggish kinetics,thermodynamic stability,inadequate cycling stability,and difficulties in activation impede the commercial utilization of Mg-based composites.Research indicates that reducing material dimensions to the nanoscale represents an efficacious strategy to address these issues.In this work,we systematically analyze the impact of nanosizing on Mg-based composites from three perspectives:nano-substrate modulation,nano-catalyst construction,and nano-catalytic mechanism.This analysis aims to provide guidance for the optimization and development of nanosizing strategies.For the regulation of nanosizing of Mg-based composites,the nanosizing of multi-element micro-alloyed Mg-rich systems,the integrated synthesis of multi-element multi-component nano-catalysts,and the coexistence of multiple nano-catalytic mechanisms are proposed in the light of the current state of the art research,artificial intelligence technology,and advanced characterization technology to achieve efficient,multidimensional,and simultaneous regulation of the hydrogen storage performance of Mg-based composites.This paper also envisions future directions and potential applications,emphasizing the importance of interdisciplinary approaches that integrate material science,chemistry,and computational modeling to overcome existing limitations and unlock the full potential of Mg-based hydrogen storage technologies. 展开更多
关键词 Nanosizing Mg-based materials substrate modulation Catalyst Catalytic mechanism
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Fading on the beach:pigmentation plasticity adjusts coloration to substrate type in coastal Western spadefoot toads
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作者 Léa Lorrain-Soligon Frédéric Robin +3 位作者 Vincent Lelong Sébastien Palier Marko Jankovic Françis Brischoux 《Current Zoology》 2025年第5期593-602,共10页
Animal species exhibit a wide range of coloration and patterns,which are under strong selection and often linked to individual quality,influencing mate choice,recognition,signaling,and interspecific interactions such ... Animal species exhibit a wide range of coloration and patterns,which are under strong selection and often linked to individual quality,influencing mate choice,recognition,signaling,and interspecific interactions such as predator avoidance.In amphibians,coloration can vary based on individual traits as well as environmental conditions,including the coloration of their environment.In this study,we described the dorsal coloration(body coloration reticulated by dark patches)in 676 Western spadefoot toads(Pelobates cultripes)from the French Atlantic coast,comparing color variations across different substrates.In addition,we assessed color change in 18 toads transferred between bright and dark substrates.We demonstrated that the dorsal coloration varies based on capture locations(beach vs.inland)and associated substrate types(bright vs.dark),suggesting background color matching.We showed more pronounced effects in females,which might reflect varying predation risks.Experimentally,we showed that individuals can rapidly adjust their coloration to match the substrate within 24 h.Rapid color changes in response to substrate type indicate significant pigmentation plasticity.Bright individuals from sandy substrates showed less dorsal background(body)color change than dark inland individuals,while patch coloration responded differently depending on the substrate of origin.These findings highlight the complex interactions between substrate type,sex,and pigmentation plasticity.These interactions have potential costs and benefits,which might be linked to melanin production,which warrant further investigation. 展开更多
关键词 AMPHIBIANS background color matching INLAND PATCHES sex-dependent substrate
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Atrial fibrillation substrate mapping with emphasis on voltage-based guidance
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作者 Edward J Ciaccio Henry H Hsia +4 位作者 Hirad Yarmohammadi Elaine Y Wan MD Nicholas S Peters Deepak Saluja Angelo B Biviano 《World Journal of Cardiology》 2025年第11期1-18,共18页
Voltage substrate mapping is a promising tool for the treatment of atrial fibrillation(AF).It is helpful to detect atrial fibrosis,which includes areas with low bipolar voltage,heterogeneous conduction properties,and ... Voltage substrate mapping is a promising tool for the treatment of atrial fibrillation(AF).It is helpful to detect atrial fibrosis,which includes areas with low bipolar voltage,heterogeneous conduction properties,and shortened effective refractory period.The voltage amplitude is typically defined as the maximal peakto-peak level within a specified time window of interest.Contemporary electroanatomic mapping platforms now enable many thousands of data points to be mapped,so that a geometric model of the atrial endocardium is constructable over a short period of time.This mapping procedure is often done with bipolar electrodes to cancel the far-field signal.The recording site coordinates are projected onto an atrial shell,with interpolation of the voltage data across the shell surface.The amplitude of the recorded bipolar electrogram depicted on the threedimensional shell provides detailed information for substrate mapping.Wherever there are areas of low peak-to-peak voltage,it is thought to mark the presence of abnormal tissue properties and conduction.However,uncontrolled variables and environmental factors affecting voltage level include the oncoming electrical activation wavefront direction,the catheter incidence angle,the force applied to the catheter,and the region-variable shape and structure of atrial tissue.Techniques and settings to acquire atrial voltage data for AF analysis have not been standardized.Methods to characterize atrial electrograms are also presently limited.These factors affect quality and reproducibility of the mapping results.Herein,voltage substrate mapping and its variables pertaining to AF and radiofrequency ablation are described and discussed,with suggestions for future work efforts. 展开更多
关键词 Ablation Atrial fibrillation Sinus rhythm substrate mapping VOLTAGE
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Fabrication of Porous SiC Coatings on Quartz Substrates by Laser Chemical Vapor Deposition
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作者 YANG Meijun CHEN Rui +4 位作者 XU Qingfang GUO Bingjian LIU Kai TU Rong ZHANG Song 《Journal of Wuhan University of Technology(Materials Science)》 2025年第2期330-337,共8页
Laser etching and laser chemical vapor deposition(LCVD)techniques were proposed for the rapid preparation of high-purity,strongly bonded SiC porous micro-nano-coatings on quartz substrates.The laser serves as an exter... Laser etching and laser chemical vapor deposition(LCVD)techniques were proposed for the rapid preparation of high-purity,strongly bonded SiC porous micro-nano-coatings on quartz substrates.The laser serves as an external driving force for the vertical growth of SiC whiskers,facilitating the formation of a porous nanostructure that resembles coral models found in the macroscopic biological world.The porous nanostructures are beneficial for reducing thermal expansion mismatch and relieving residual stress.It is capable of eliminating the cracks on the surface of SiC coatings as well as enhancing the bonding of SiC coatings with quartz substrates to avoid coating detachment. 展开更多
关键词 laser etching laser CVD quartz substrate SiC coating
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Utilization of Spent Mushroom Substrate and Local Organic Wastes as Sustainable Growth Media for Enhanced Cocoa Seedling Development
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作者 Karupakorn Laeid-on Arunrussamee Sangsila +1 位作者 Worrawat Promden Tepporn Lomarak 《Journal of Environmental & Earth Sciences》 2025年第1期540-549,共10页
This study examines the effects of germination substrates incorporating spent mushroom substrate(SMS)and locally sourced organic materials on the growth and vigor of cocoa seedlings.Seven treatments were evaluated usi... This study examines the effects of germination substrates incorporating spent mushroom substrate(SMS)and locally sourced organic materials on the growth and vigor of cocoa seedlings.Seven treatments were evaluated using a Completely Randomized Design(CRD),comprising combinations of coconut coir,rice husk,sugarcane bagasse,and biochar.Key findings reveal that treatments combining SMS,sugarcane bagasse,and either coconut coir or biochar(T6 and T7)achieved significantly higher survival rates and Dickson Quality Index(DQI)scores compared to conventional soil(T1).These treatments provided favorable chemical properties,including optimal pH,electrical conductivity,and nutrient content(N,P,K),which are critical for cocoa seedling development.The results suggest that using SMS with agricultural waste as an alternative germination medium can reduce cultivation costs,enhance seedling growth,and contribute to sustainable agricultural practices by repurposing organic waste.This approach not only offers cost-effective benefits for farmers but also mitigates environmental impacts associated with waste disposal. 展开更多
关键词 Spent Mushroom substrate Organic Materials Seeding Cocoa
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Spherical Indentation on a Piezoelectric Semiconductor Film/Elastic Substrate System
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作者 Shijing Gao Guoquan Nie +1 位作者 Jinxi Liu Weiqiu Chen 《Acta Mechanica Solida Sinica》 2025年第5期872-883,共12页
We study the axisymmetric frictionless indentation problem of a piezoelectric semiconductor(PSC)thin film perfectly bonded to a semi-infinite isotropic elastic substrate by a rigid and insulating spherical indenter.Th... We study the axisymmetric frictionless indentation problem of a piezoelectric semiconductor(PSC)thin film perfectly bonded to a semi-infinite isotropic elastic substrate by a rigid and insulating spherical indenter.The Hankel integral transformation is first employed to derive the general solutions for the governing differential equations of the PSC film and elastic substrate.Then,using the boundary and interface conditions,the complicated indentation problem is reduced to numerically solve a Fredholm integral equation of the second kind.Numerical results are given to demonstrate the effects of semiconducting property,film thickness as well as Young’s modulus and Poisson’s ratio of the substrate on the indentation responses.The obtained findings will contribute to the establishment of indentation experiments for PSC film/substrate systems. 展开更多
关键词 INDENTATION Piezoelectric semiconductor Singular integral equation substrate effect Thin film
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Influence of Bromo-Aromatic Substrates on Direct Arylation of EDOTs toward Higher Molecular Conjugate Polymer
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作者 Xi-Lin Pei Quan Yang +3 位作者 Yan-Lu Sun Wei Wu Jian-Yong Yu Yong He 《Chinese Journal of Polymer Science》 2025年第5期718-729,共12页
The influence of the electronic and steric properties of bromoaromatic substrates on direct arylation polymerization for synthesizing high-molecular-weight conjugated polymers was investigated through a combination of... The influence of the electronic and steric properties of bromoaromatic substrates on direct arylation polymerization for synthesizing high-molecular-weight conjugated polymers was investigated through a combination of experiments and calculations.Bromo-aromatic substrates with electron-withdrawing fluoro substituents exhibited higher yields and degrees of polymerization under PPh3-assisted conditions compared to those with electron-donating or bulky methyl substituents.Additionally,excessive steric hindrance at ortho-sites or overly electrondeficient dibromoaromatic substrates leads to reaction inactivation.Calculations indicated that electron-withdrawing substituents enhanced the electrophilicity of arylpalladium-PPh3intermediates,facilitating the activation of electron-rich arylative substrates and promoting polymer growth.Furthermore,steric hindrance from the substituents can influence the preferred reaction pathway,thereby increasing the real reaction barriers.Both experimental and computational results suggest that bromoaromatic substrates with optimized electron-deficient characteristics significantly improve monomer conversion and polymerization efficiency with n-hexylmethylether-substituted EDOT.These findings clarify how the electronic and steric properties of bromo-aromatic substrates affect EDOT derivative activation and are expected to aid in optimizing the polymerization conditions for the preparation of high-molecular-weight conjugated polymers. 展开更多
关键词 3 4-Ethylenedioxythiophene Direct arylation polymerization Bromo-aromatic substrate Concerted metalation-deptonation
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Recent progress on high-precision construction of nanoarchitectured SERS substrates for ultrasensitive bio-medical sensors
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作者 Heguang Liu Ben Mou +8 位作者 Jinxin Li Na Tian Yiming Feng Xiaodong Cui Yury Kapitonov Huageng Liang Caiyin You Yuan Li Tianyou Zhai 《Advanced Powder Materials》 2025年第4期30-57,共28页
Surface-enhanced Raman spectroscopy(SERS)has evolved from a laboratory technique to a practical tool for ultra-sensitive detection,particularly in the biomedical field,where precise molecular identification is crucial... Surface-enhanced Raman spectroscopy(SERS)has evolved from a laboratory technique to a practical tool for ultra-sensitive detection,particularly in the biomedical field,where precise molecular identification is crucial.Despite significant advancements,a gap remains in the literature,as no comprehensive review systematically addresses the high-precision construction of SERS substrates for ultrasensitive biomedical detection.This review fills that gap by exploring recent progress in fabricating high-precision SERS substrates,emphasizing their role in enabling ultrasensitive bio-medical sensors.We carefully examine the key to these advancements is the precision engineering of substrates,including noble metals,semiconductors,carbon-based materials,and two-dimensional materials,which is essential for achieving the high sensitivity required for ultrasensitive detection.Applications in biomedical diagnostics and molecular analysis are highlighted.Finally,we address the challenges in SERS substrate preparation and outline future directions,focusing on improvement strategies,design concepts,and expanding applications for these advanced materials. 展开更多
关键词 SERS SERS substrates High-precision construction Ultrasensitive bio-medical sensors Enhancement mechanism
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Thickness-dependent magnetic property of FeNi thin film grown on flexible graphene substrate
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作者 Suixin Zhan Shaokang Yuan +6 位作者 Yuming Bai Fu Liu Bohan Zhang Weijia Han Tao Wang Shengxiang Wang Cai Zhou 《Chinese Physics B》 2025年第2期448-452,共5页
Electronics over flexible substrates offer advantages of flexibility, portability and low cost, and promising applications in the areas of energy, information, defense science and medical service. In recent years, tre... Electronics over flexible substrates offer advantages of flexibility, portability and low cost, and promising applications in the areas of energy, information, defense science and medical service. In recent years, tremendous progress has been witnessed in the development of flexible wearable devices that can be potentially massively deployed. Of particular interest are intelligent wearable devices, such as sensors and storage cells, which can be integrated by flexible magnetoelectronic devices based on magnetic thin films. To examine this further, the magnetic properties of FeNi thin films with different thicknesses grown on flexible graphene substrate are investigated at room temperature. The coercivity increases with increasing thicknesses of FeNi thin film, which can be attributed to the increase of grain size and decrease of surface roughness. Moreover, the thickness modulated magnetic property shows a magnetic anisotropy shift increase with varying thicknesses of FeNi thin film by using measurements based on ferromagnetic resonance, which further enhances the resonance frequency. In addition, the resonance peak is quite stable after bending it for ten cycles. The result is promising for the future design of flexible magnetoelectronic devices. 展开更多
关键词 resonance frequency FeNi thin film flexible graphene substrate magnetic property
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