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基于数据驱动的分布式光伏发电功率预测方法研究进展
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作者 董明 李晓枫 +4 位作者 杨章 常益 任明 张崇兴 焦在滨 《电网与清洁能源》 CSCD 北大核心 2024年第1期8-17,28,共11页
从综述的角度,以分布式光伏系统为对象,分析了功率预测技术的发展情况、存在的难点以及主要影响因素,梳理了应用数据驱动方法实现功率准确预测的技术路线。再以空间相关性、历史出力功率以及气象等影响因素为切入点,梳理了光伏系统数据... 从综述的角度,以分布式光伏系统为对象,分析了功率预测技术的发展情况、存在的难点以及主要影响因素,梳理了应用数据驱动方法实现功率准确预测的技术路线。再以空间相关性、历史出力功率以及气象等影响因素为切入点,梳理了光伏系统数据驱动的功率预测研究现状,分析其相应的数据增强、时空图信息以及特征融合的手段,讨论了技术的优缺点。最后给出了功率预测数据驱动方法研究方向和发展建议。 展开更多
关键词 分布式光伏出力特性 数据驱动 数据增强 时空图信息 特征融合
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Gut microbiota dysbiosis contributes toα-synuclein-related pathology associated with C/EBPβ/AEP signaling activation in a mouse model of Parkinson’s disease
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作者 Xiaoli Fang Sha Liu +9 位作者 Bilal Muhammad Mingxuan Zheng Xing Ge Yan Xu Shu Kan yang zhang Yinghua Yu Kuiyang Zheng Deqin Geng Chun-Feng Liu 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第9期2081-2088,共8页
Parkinson’s disease is a neurodegenerative disease characterized by motor and gastrointestinal dysfunction.Gastrointestinal dysfunction can precede the onset of motor symptoms by several years.Gut microbiota dysbiosi... Parkinson’s disease is a neurodegenerative disease characterized by motor and gastrointestinal dysfunction.Gastrointestinal dysfunction can precede the onset of motor symptoms by several years.Gut microbiota dysbiosis is involved in the pathogenesis of Parkinson’s disease,whether it plays a causal role in motor dysfunction,and the mechanism underlying this potential effect,remain unknown.CCAAT/enhancer binding proteinβ/asparagine endopeptidase(C/EBPβ/AEP)signaling,activated by bacterial endotoxin,can promoteα-synuclein transcription,thereby contributing to Parkinson’s disease pathology.In this study,we aimed to investigate the role of the gut microbiota in C/EBPβ/AEP signaling,α-synuclein-related pathology,and motor symptoms using a rotenone-induced mouse model of Parkinson’s disease combined with antibiotic-induced microbiome depletion and fecal microbiota transplantation.We found that rotenone administration resulted in gut microbiota dysbiosis and perturbation of the intestinal barrier,as well as activation of the C/EBP/AEP pathway,α-synuclein aggregation,and tyrosine hydroxylase-positive neuron loss in the substantia nigra in mice with motor deficits.However,treatment with rotenone did not have any of these adverse effects in mice whose gut microbiota was depleted by pretreatment with antibiotics.Importantly,we found that transplanting gut microbiota derived from mice treated with rotenone induced motor deficits,intestinal inflammation,and endotoxemia.Transplantation of fecal microbiota from healthy control mice alleviated rotenone-induced motor deficits,intestinal inflammation,endotoxemia,and intestinal barrier impairment.These results highlight the vital role that gut microbiota dysbiosis plays in inducing motor deficits,C/EBPβ/AEP signaling activation,andα-synuclein-related pathology in a rotenone-induced mouse model of Parkinson’s disease.Additionally,our findings suggest that supplementing with healthy microbiota may be a safe and effective treatment that could help ameliorate the progression of motor deficits in patients with Parkinson’s disease. 展开更多
关键词 C/EBP/AEP signaling pathway ENDOTOXEMIA fecal microbiota transplantation intestinal barrier intestinal inflammation microbiota-gut-brain axis Parkinson’s disease
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Mechanical behaviours of bedded sandstone under hydromechanical coupling
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作者 Junwen zhang Zhixiang Song +7 位作者 Lichao zhang Shaokang Wu Shanyong Wang yang zhang Xukai Dong Jinxin Wang Yanbo Han Baohua Kan 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第4期1245-1261,共17页
The combination of the dipping effect and hydromechanical(H-M)coupling effect can easily lead to water inrush disasters in water-rich roadways with different dip angles in coal mines.Therefore,H-M coupling tests of be... The combination of the dipping effect and hydromechanical(H-M)coupling effect can easily lead to water inrush disasters in water-rich roadways with different dip angles in coal mines.Therefore,H-M coupling tests of bedded sandstones under identical osmotic pressure and various confining pressures were conducted.Then,the evolution curves of stress-strain,permeability and damage,macro-and mesoscopic failure characteristics were obtained.Subsequently,the mechanical behaviour was characterized,and finally the failure mechanism was revealed.The results showed that:(1)The failure of the sandstone with the bedding angle of 45°or 60°was the structure-dominant type,while that with the bedding angle of 0°,30°or 90°was the force-dominant type.(2)When the bedding angle was in the range of(0°,30°)or(45°,90°),the confining pressure played a dominant role in influencing the peak strength.However,withinβ∈(30°,45°),the bedding effect played a dominant role in the peak strength.(3)With the increase in bedding angle,the cohesion increased first,then decreased and finally increased,while the internal friction angle was the opposite.(4)When the bedding angle was 0°or 30°,the“water wedging”effect and the“bedding buckling”effect would lead to the forking or converging shear failure.When the bedding angle was 45°or 60°,the sliding friction effect would lead to the shear slipping failure.When the bedding angle was 90°,the combination of the“bedding buckling”effect and shear effect would lead to the mixed tension-shear failure.The above conclusions obtained are helpful for the prevention of water inrush disasters in water-rich roadways with different dips in coal mines. 展开更多
关键词 Hydromechanical coupling Bedded sandstones Mechanical behaviour Bedding effect Failure mechanism
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Experimental study of core MHD behavior and a novel algorithm for rational surface detection based on profile reflectometry in EAST
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作者 叶凯萱 周振 +20 位作者 张涛 马九阳 王嵎民 李恭顺 耿康宁 吴茗甫 文斐 黄佳 张洋 邵林明 杨书琪 钟富彬 高善露 喻琳 周子强 向皓明 韩翔 张寿彪 李国强 高翔 the EAST Team 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第3期66-75,共10页
Microwave reflectometry is a powerful diagnostic that can measure the density profile and localized turbulence with high spatial and temporal resolution and will be used in ITER,so understanding the influence of plasm... Microwave reflectometry is a powerful diagnostic that can measure the density profile and localized turbulence with high spatial and temporal resolution and will be used in ITER,so understanding the influence of plasma perturbations on the reflect signal is important.The characteristics of the reflect signal from profile reflectometry,the time-of-flight(TOF)signal associated with the MHD instabilities,are investigated in EAST.Using a 1D full-wave simulation code by the Finite-DifferenceTime-Domain(FDTD)method,it is well validated that the local density flattening could induce the discontinuity of the simulated TOF signal and an obvious change of reflect amplitude.Experimental TOF signals under different types of MHD instabilities(sawtooth,sawtooth precursors and tearing mode)are studied in detail and show agreement with the simulation.Two new improved algorithms for detecting and localizing the radial positions of the low-order rational surface,the cross-correlation and gradient threshold(CGT)method and the 2D convolutional neural network approach(CNN)are presented for the first time.It is concluded that TOF signal analysis from profile reflectometry can provide a straightforward and localized measurement of the plasma perturbation from the edge to the core simultaneously and may be a complement or correction to the q-profile control,which will be beneficial for the advanced tokamak operation. 展开更多
关键词 MHD instabilities profile reflectometry rational surface detection convolutional neural network(CNN) EAST tokamak
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Glycogen metabolism-mediated intercellular communication in the tumor microenvironment influences liver cancer prognosis
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作者 yang zhang NANNAN QIN +6 位作者 XIJUN WANG RUI LIANG QUAN LIU RUOYI GENG TIANXIAO JIANG YUNFEI LIU JINWEI LI 《Oncology Research》 SCIE 2024年第3期563-576,共14页
Glycogen metabolism plays a key role in the development of hepatoellular carcinoma(HCC),but the function of glycogen metabolism genes in the tumor microenvironment(TME)is still to be elucidated.Single cell RNA-seq dat... Glycogen metabolism plays a key role in the development of hepatoellular carcinoma(HCC),but the function of glycogen metabolism genes in the tumor microenvironment(TME)is still to be elucidated.Single cell RNA-seq data were obtained from ten HCC tumor samples totaling 64,545 cells and 65 glycogen metabolism genes were analyzed bya nonnegative matrix factorization(NMF).The prognosis and immune response of new glycogen TME cell dusters were predicted by using HCC and immunotherapy cohorts from public databases.HOC single cell analysis was divided into fibroblasts,NT T cells,macrophages,endothelial clls,and B cells,which were separately divided into new cell clusters by glycogen metabolism gene annotation.Pseudo temporal trajectory analysis demonstrated the temporal differentiation trajectory of different glycogen subtype cell dusters.Cellular communication analysis revealed extensive interactions between endothelial cells with glycogen metabolizing TME cell.related subtypes and diferent glycogen subtype cell clusters.SCENIC analysis of transcription factors upstream of TME cell clusters with different glycogen metabolism.In addition,TME cell dusters of glycogen metabolism were found to be enriched in expression in CAF subtypes,CD8 depleted,M1,and M2 types.Bulk seq analysis showed the prognostic signifcance of glycogen metabolism.mediated TME cell dusters in HCC,while a significant immune response was found in the immunotherapy cohort in patients treated with immune checkpoint blockade(ICB),especially for CAFs,T cells,and macrophages In summary,our study reveals for the first time that glycogen metabolism mediates intercellular communication in the hepatocellular carcinoma microenvironment while elucidating the anti-tumor mechanisms and immune prognostic responses of different subtypes of cell dusters. 展开更多
关键词 Glycogen metabolism Metabolic map Single cell Tumor microenvironment Liver cancer PROGNOSIS IMMUNOTHERAPY
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Changes in posterior corneal elevation after small incision lenticule extraction for different myopic diopters
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作者 Xiao-Tong Sun yang zhang +5 位作者 Xiao-Kun Mei Nan-Nan Zheng Ling-Zhi Niu Xiao-Li Qu Ai-Ping Song Jian Zhuo 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第3期491-498,共8页
●AIM:To study the changes and effect factors of posterior corneal surface after small incision lenticule extraction(SMILE)with different myopic diopters.●METHODS:Ninety eyes of 90 patients who underwent SMILE were i... ●AIM:To study the changes and effect factors of posterior corneal surface after small incision lenticule extraction(SMILE)with different myopic diopters.●METHODS:Ninety eyes of 90 patients who underwent SMILE were included in this retrospective study.Patients were allocated into three groups based on the preoperative spherical equivalent(SE):low myopia(SE≥-3.00 D),moderate myopia(-3.00 D>SE>-6.00 D)and high myopia(SE≤-6.00 D).Posterior corneal surfaces were measured by a Scheimpflug camera preoperatively and different postoperative times(1wk,1,3,6mo,and 1y).Posterior mean elevation(PME)at 25 predetermined points of 3 concentric circles(2-,4-,and 6-mm diameter)above the best fit sphere was analyzed.●RESULTS:All surgeries were completed uneventfully and no ectasia was found through the observation.The difference of myopia group was significant at the 2-mm ring at 1 and 3mo postoperatively(1mo:P=0.017;3mo:P=0.018).The effect of time onΔPME was statistically significant(2-mm ring:P=0.001;4-mm ring:P<0.001;6-mm ring:P<0.001).The effect of different corneal locations onΔPME was significant except 1wk postoperatively(1mo:P=0.000;3mo:P=0.000;6mo:P=0.001;1y:P=0.001).Posterior corneal stability was linearly correlated with SE,central corneal thickness,ablation depth,residual bed thickness,percent ablation depth and percent stromal bed thickness.●CONCLUSION:The posterior corneal surface changes dynamically after SMILE.No protrusion is observed on the posterior corneal surface in patients with different degrees of myopia within one year after surgery.SMILE has good stability,accuracy,safety and predictability. 展开更多
关键词 MYOPIA posterior corneal elevation corneal ectasia small incision lenticule extraction
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Spatio-temporal Evolution and Optimization of Landscape Ecological Risk in Karst Mountainous Areas
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作者 Fangfang DENG Zhongfa ZHOU +4 位作者 Denghong HUANG yang zhang Fuxianmei zhang Shuanglong DU Yue yang 《Meteorological and Environmental Research》 2024年第1期16-26,共11页
[Objective]The ecological vulnerability and landscape ecological risk of karst mountainous areas have increased as a result of enhanced disturbance of natural resources by human activities.This paper aimed to explore ... [Objective]The ecological vulnerability and landscape ecological risk of karst mountainous areas have increased as a result of enhanced disturbance of natural resources by human activities.This paper aimed to explore the characteristics of ecological risk evolution under different landscape patterns in the region,with a view to providing reference for land classification protection,sustainable use of resources and regional ecological risk optimization in karst mountainous areas.[Method]Taking Huangping County,a typical karst mountainous area,as an example,eight evaluation factors of natural and landscape patterns were selected to construct a landscape ecological risk evaluation model,to quantitatively explore the spatio-temporal evolution of landscape ecological risk and the trend of risk level transfer in the study area from 2010-2018,and to reveal the complex relationship between ecological risk and topography in karst mountainous areas.[Result]①From 2010 to 2018,land use types changed to different degrees,with the most amount of woodland transferred out(1627.37 hm 2)and the most amount of construction land transferred in(1303.93 hm 2);a total of 3552.31 hm 2 of land was transferred,with a change ratio of 2.13%,and there was a significant conversion between construction land,arable land,and woodland.②From 2010 to 2018,the landscape ecological risk in the study area changed significantly,and the landscape ecological risk index decreased from 0.3441 to 0.1733,showing an upward and then downward trend;the landscape ecological risk of the whole region was dominated by low-risk and lower-risk zones,and the ecological risk level generally shifted from a high level to a low level,and the ecological environment was improved.③There was a negative correlation between ecological risk and topographic position,and high-risk zones were mainly distributed among low topographic zones;with the change of time,the advantage of risk level for the selection of topography was gradually weakened,and the influence of anthropogenic factors on the ecological risk of the landscape was becoming more and more prominent.[Conclusion]This paper can provide theoretical basis for land use optimization and ecological protection in karst mountainous areas. 展开更多
关键词 Karst mountainous area Landscape pattern Landscape ecological risk index Terrain distribution index
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基于PBL+CBL联合教学提升神经病学教学实效性研究
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作者 杨樟 蔡刚 高子丹 《科教导刊》 2024年第4期156-158,共3页
目的:本研究以神经病学教学为例,旨在评估基于问题的学习(problem-basedlearning,PBL)和基于案例的学习(case-based learning,CBL)联合教学的有效性。方法:以贵州医科大学临床医学专业学生为研究对象,分为PBL―CBL组和传统模式组,进行... 目的:本研究以神经病学教学为例,旨在评估基于问题的学习(problem-basedlearning,PBL)和基于案例的学习(case-based learning,CBL)联合教学的有效性。方法:以贵州医科大学临床医学专业学生为研究对象,分为PBL―CBL组和传统模式组,进行脑血管病课程教学。通过课前和课后测试,问卷调查,评估学生的观点,并观察学生对学习的满意度。结果:PBL―CBL组的课前和课后测试总分显著高于传统模式组(P<0.05),基础知识无差异(P>0.05);PBL―CBL组在学习动机、自学能力和理解等得分显著优于传统模式组(P<0.05)。结论:PBL―CBL联合教学能有效提高神经病学教学质量,增强学生的临床技能,是提高医学生表现、提高临床技能的有效方法。 展开更多
关键词 神经病学 基于案例的学习 基于问题的学习 有效性
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碳纳米管对3D打印混凝土流变性能及力学性能的影响 被引量:3
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作者 赵宇 武喜凯 +3 位作者 朱伶俐 杨章 杨若凡 管学茂 《材料导报》 EI CAS CSCD 北大核心 2023年第6期109-114,共6页
碳纳米管(MWCNTs)是一种性能优良的纳米材料,将其掺入3D打印混凝土(3DPC)中不仅会对基体内部微裂纹的生成和扩展以及3D打印混凝土的宏观力学性能产生显著影响,而且会影响新拌3D打印混凝土的流变性能。为了明确碳纳米管对3D打印混凝土性... 碳纳米管(MWCNTs)是一种性能优良的纳米材料,将其掺入3D打印混凝土(3DPC)中不仅会对基体内部微裂纹的生成和扩展以及3D打印混凝土的宏观力学性能产生显著影响,而且会影响新拌3D打印混凝土的流变性能。为了明确碳纳米管对3D打印混凝土性能的影响,通过设置六种碳纳米管掺量(0%、0.01%、0.02%、0.05%、0.08%、0.1%),研究了碳纳米管的掺量对3D打印凝土流变性能及力学性能的影响,并基于SEM测试结果进行了微观分析。研究结果表明:随着碳纳米管掺量的增加,3D打印混凝土的流动度逐渐下降,静态屈服应力、动态屈服应力逐渐增加。各龄期的抗折强度均随着碳纳米管掺量的增加而增大。随碳纳米管掺量的增加,3D打印混凝土的抗压强度先增大后减小,当碳纳米管掺量为0.05%时,其抗压强度最大。SEM结果显示,碳纳米管可以起到桥接和填充作用,能与基体紧密连接,阻止3D打印混凝土内部微裂缝和孔洞的生成与扩展,在较低掺量(不超过0.05%)下即能显著改善3D打印混凝土的微观结构。 展开更多
关键词 3D打印混凝土 碳纳米管 流变特性 力学性能
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Comparison of the Effectiveness of Marked Suction Tubes vs. Plain Suction Tubes in Pediatric Mechanically Ventilated Patients
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作者 Kexin yang yang zhang +5 位作者 Menghui Duan Qiuju Liang Jianfei zhang Ping Kong Mengqi Duan Xiangwei Chen 《Open Journal of Pediatrics》 2023年第6期774-784,共11页
Introduction: Endotracheal suction plays a crucial role in the management of mechanically ventilated patients. This study aims to evaluate the clinical effectiveness and safety of suction tubes with markings in mechan... Introduction: Endotracheal suction plays a crucial role in the management of mechanically ventilated patients. This study aims to evaluate the clinical effectiveness and safety of suction tubes with markings in mechanically ventilated pediatric patients. Materials and Methods: A randomized assignment was carried out on a cohort of 52 pediatric patients who underwent mechanical ventilation in the Pediatric Intensive Care Unit at the Third Affiliated Hospital of Sun Yat-sen University, covering the period from January 2022 to December 2022. These patients were divided into two groups: an improved group (n = 26) utilizing marked suction tubes, and a regular group (n = 26) employing conventional suction tubes. The objective of our study was to evaluate the clinical effectiveness of marked suction tubes. Results: The effects of the improved group on the vital signs of children undergoing mechanical ventilation were small and statistically significant compared with the regular group (p < 0.05). Additionally, the improved group exhibited a reduced frequency of sputum suction, shorter mechanical ventilation duration, and fewer days of hospitalization in the PICU compared to the regular group during the ventilation period. Notably, the difference in the duration of PICU hospitalization was statistically significant (p < 0.05). Moreover, the incidence of adverse reactions in the improved group was notably lower, with statistically significant differences observed in airway mucous membrane damage and irritating cough when compared to the regular group (p < 0.05). Conclusion: The utilization of marked suction tubes provides clinical nurses with clear guidance for performing suctioning with ease, efficiency and safety. Consequently, advocating for the widespread implementation of marked suction tubes in clinical practice is a commendable pursuit. 展开更多
关键词 Marked Suction Tubes Endotracheal Suction Mechanical Ventilation Different Depth of Aspiration
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钢渣-矿渣复合水泥基材料3D打印性能
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作者 朱伶俐 杨章 +2 位作者 赵宇 管学茂 武喜凯 《材料导报》 CSCD 北大核心 2023年第12期107-112,共6页
为了提高固体废弃物的资源化利用,探究利用钢渣制备3D打印水泥基材料的可行性,研究了钢渣、矿渣的质量比对复合水泥基材料流变特性、可打印性和力学性能的影响规律。结果表明,随着钢渣质量的增加,浆体的流动度和静态屈服应力增大,塑性... 为了提高固体废弃物的资源化利用,探究利用钢渣制备3D打印水泥基材料的可行性,研究了钢渣、矿渣的质量比对复合水泥基材料流变特性、可打印性和力学性能的影响规律。结果表明,随着钢渣质量的增加,浆体的流动度和静态屈服应力增大,塑性粘度减小,可挤出性增强,变形率降低,同时抗压强度显著降低。通过Zeta电位测试发现,随着钢渣掺量的增加,Zeta电位绝对值变小,胶体颗粒间引力增大,导致静态屈服应力增大。而随着矿渣掺量的增加,浆体固含量增多,固体颗粒间摩擦加剧,产生了更多絮凝结构和网状结构,提高了浆体的塑性粘度。 展开更多
关键词 3D打印水泥基材料 流变 可打印性 钢渣 矿渣
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碳酸锂对3D打印水泥基材料早期性能影响研究
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作者 朱伶俐 杨章 +2 位作者 赵宇 管学茂 武喜凯 《混凝土》 CAS 北大核心 2023年第9期49-54,共6页
3D打印水泥基材料需要良好的形状保持能力,早期性能的发展对3D打印水泥基材料的配合比设计与优化调控至关重要。研究了碳酸锂掺量对3D打印水泥基材料流变特性、湿胚强度、可建造性的影响规律。研究发现:碳酸锂的加入使得砂浆湿胚强度和... 3D打印水泥基材料需要良好的形状保持能力,早期性能的发展对3D打印水泥基材料的配合比设计与优化调控至关重要。研究了碳酸锂掺量对3D打印水泥基材料流变特性、湿胚强度、可建造性的影响规律。研究发现:碳酸锂的加入使得砂浆湿胚强度和静态屈服应力呈现指数级增长,随着碳酸锂的掺量达到2‰、3.5‰、5‰,其初凝时间分别为94、62、39 min;龄期为10 min时碳酸锂掺量为5‰砂浆的静态屈服应力值是未掺入碳酸锂的4倍;碳酸锂掺量为0、2‰、3.5‰、5‰的打印层数分别为26、22、28、32层。当静态屈服应力值达到3544 Pa,砂浆的挤出性变差对可建造性造成了负面影响,底层砂浆强度的快速发展则能够提高可建造性。 展开更多
关键词 凝结时间 3D打印水泥基材料 流变特性 湿胚强度 可建造性
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硬段结构对含二硫键自修复聚氨酯性能的影响 被引量:2
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作者 张阳 周雨琪 +3 位作者 段文鹏 李博 许勇 孙妮娟 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2023年第4期8-16,共9页
硬段结构的研究对指导制备兼顾力学性能与自修复性能的聚氨酯弹性体具有重要的意义。文中分别以4,4'-二苯基甲烷二异氰酸酯(MDI)、4,4'-二环己基甲烷二异氰酸酯(HMDI)、甲苯二异氰酸酯(TDI)、异佛尔酮二异氰酸酯(IPDI)及双(2-... 硬段结构的研究对指导制备兼顾力学性能与自修复性能的聚氨酯弹性体具有重要的意义。文中分别以4,4'-二苯基甲烷二异氰酸酯(MDI)、4,4'-二环己基甲烷二异氰酸酯(HMDI)、甲苯二异氰酸酯(TDI)、异佛尔酮二异氰酸酯(IPDI)及双(2-羟基乙基)二硫醚(HEDS)为硬段部分,聚己内酯二元醇为软段部分,制备了一系列含脂肪族二硫键的自修复聚氨酯,探究了不同异氰酸酯、硬段含量和扩链剂对其力学性能与自修复性能的影响。结果表明,对于异氰酸酯结构来讲,脂环族异氰酸酯制备的自修复聚氨酯具备更好的力学性能与自修复性能;对于脂环族异氰酸酯体系聚氨酯的硬段含量而言,一定范围越高,二硫键与氢键的含量也越高,越有利于材料的力学性能与自修复性能;对于扩链剂结构来讲,脂肪族二硫键主要是促进较高温度条件下的自修复性能,对于室温自修复性能起到的作用有限。 展开更多
关键词 脂肪族二硫键 自修复 聚氨酯 硬段
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电催化二氧化碳还原催化剂、电解液、反应器和隔膜研究进展 被引量:1
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作者 彭芦苇 张杨 +2 位作者 何瑞楠 徐能能 乔锦丽 《物理化学学报》 SCIE CAS CSCD 北大核心 2023年第12期39-62,共24页
人类社会的正常运转非常依赖化石能源,然而化石能源的消耗已导致能源危机和环境污染,同时空气中CO_(2)的含量从工业革命以来一直攀升。将CO_(2)通过催化反应转化为高附加值的燃料和化学品,不仅可以缓解环境问题,还开辟了一种燃料合成新... 人类社会的正常运转非常依赖化石能源,然而化石能源的消耗已导致能源危机和环境污染,同时空气中CO_(2)的含量从工业革命以来一直攀升。将CO_(2)通过催化反应转化为高附加值的燃料和化学品,不仅可以缓解环境问题,还开辟了一种燃料合成新路径,其中电催化CO_(2)还原技术由于条件温和、反应可控、对环境友好和产物众多受到广泛关注。电催化CO_(2)技术有四个关键步骤:(1)电荷传输(电子从导电基底传输到电催化剂);(2)表面转化(CO_(2)吸附在催化剂表面并被活化);(3)电荷传输(电子从催化剂表面传输到CO_(2)中间体);(4)传质效应(CO_(2)从电解质扩散到催化剂表面,产物以反向路径扩散),前两个步骤依赖于具有丰富有效活性位点的催化剂,后两个步骤依赖于电解质的性质、隔膜的类型和电解池的配置。本文从工业化和商业化电催化CO_(2)技术出发,系统地归纳催化剂的发展、电解液的影响、反应器的进展和隔膜的类型,最后对电催化CO_(2)还原的产业化进行展望。 展开更多
关键词 电催化二氧化碳还原反应 催化剂 电解液 隔膜 反应器 工业化
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用于高灵敏快速核酸检测的荧光碳点
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作者 常建桥 许慧敏 +4 位作者 谢文菁 张洋 祁玲 范楼珍 李勇 《物理化学学报》 SCIE CAS CSCD 北大核心 2023年第12期168-175,共8页
逆转录-实时荧光定量聚合酶链式反应(RT-qPCR)已经广泛应用于核酸检测。然而,如何实现准确、快速即时检测仍然是亟待解决的关键问题。本研究设计了一种使用胍基修饰的荧光碳点(GCDs),用于高灵敏度以及高特异性的快速核酸检测。当GCDs与... 逆转录-实时荧光定量聚合酶链式反应(RT-qPCR)已经广泛应用于核酸检测。然而,如何实现准确、快速即时检测仍然是亟待解决的关键问题。本研究设计了一种使用胍基修饰的荧光碳点(GCDs),用于高灵敏度以及高特异性的快速核酸检测。当GCDs与分子信标(Beacon)通过氢键作用结合后,GCDs的荧光被Beacon的荧光基团淬灭。当遇到目标核酸(Target DNA)之后,Beacon与Target DNA进行碱基互补配对,GCDs与Beacon脱离,GCDs自身荧光恢复。基于这种灵敏的荧光“off-on”,可实现在5 min内快速准确核酸检测,并可检测到体系内0.005 fmol∙L^(−1)(约300 copys∙mL^(−1))的核酸序列,相比于RT-qPCR所需要的2–4 h,该方法不需要进行核酸扩增,缩短了检测时间,有望为目前的核酸检测提供一个便捷有效的方法。 展开更多
关键词 荧光碳点 胍基修饰 核酸检测 新冠病毒 高特异性 高灵敏度 即时检测
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Characterization and evaluation of brittleness of deep bedded sandstone from the perspective of the whole life-cycle evolution process 被引量:3
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作者 Zhixiang Song Junwen zhang +2 位作者 yang zhang Xukai Dong Shanyong Wang 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第4期481-502,共22页
The quantitative determination and evaluation of rock brittleness are crucial for the estimation of excavation efficiency and the improvement of hydraulic fracturing efficiency.Therefore,a“three-stage”triaxial loadi... The quantitative determination and evaluation of rock brittleness are crucial for the estimation of excavation efficiency and the improvement of hydraulic fracturing efficiency.Therefore,a“three-stage”triaxial loading and unloading stress path is designed and proposed.Subsequently,six brittleness indices are selected.In addition,the evolution characteristics of the six brittleness indices selected are characterized based on the bedding effect and the effect of confining pressure.Then,the entropy weight method(EWM)is introduced to assign weight to the six brittleness indices,and the comprehensive brittleness index Bcis defined and evaluated.Next,the new brittleness classification standard is determined,and the brittleness differences between the two stress paths are quantified.Finally,compared with the previous evaluation methods,the rationality of the proposed comprehensive brittleness index Bcis also verified.These results indicate that the proposed brittleness index Bccan reflect the brittle characteristics of deep bedded sandstone from the perspective of the whole life-cycle evolution process.Accordingly,the method proposed seems to offer reliable evaluations of the brittleness of deep bedded sandstone in deep engineering practices,although further validation is necessary. 展开更多
关键词 BRITTLENESS Deep bedded sandstone Whole life-cycle evolution process Bedding effect Effect of confining pressure Entropy weight method
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石墨纳米片的原位分散及对聚丙烯力学性能的影响
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作者 汪国美 张阳 +1 位作者 吴宏 郭少云 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2023年第7期48-55,共8页
石墨纳米片(GNP)在聚合物基体中的分散状态和界面相互作用是决定GNP/聚合物复合材料力学性能的关键因素。文中采用与聚丙烯(PP)共球磨剥离石墨得到GNP均匀包覆PP的母粒,进一步与PP熔融共混制备了PP/GNP复合材料。结果表明,与纯石墨和石... 石墨纳米片(GNP)在聚合物基体中的分散状态和界面相互作用是决定GNP/聚合物复合材料力学性能的关键因素。文中采用与聚丙烯(PP)共球磨剥离石墨得到GNP均匀包覆PP的母粒,进一步与PP熔融共混制备了PP/GNP复合材料。结果表明,与纯石墨和石墨烯相比,GNP与PP基体之间的界面相互作用更强,扫描电镜分析显示GNP分散更均匀,添加0.7%GNP的复合材料经差示扫描量热分析后发现,其结晶温度(Tc)显著提高。PP/GNP复合材料的拉伸强度和冲击强度相对于纯PP分别提升了33.34%和33.47%。该分散方法在开发其他高性能多功能GNP/聚合物复合材料方面具有巨大潜力。 展开更多
关键词 聚丙烯 石墨纳米片 干法球磨 力学性能
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Channel Estimation for OTFS System over Doubly Spread Sparse Acoustic Channels 被引量:2
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作者 yang zhang Qunfei zhang +1 位作者 Chengbing He Chao Long 《China Communications》 SCIE CSCD 2023年第1期50-65,共16页
This paper addresses sparse channels estimation problem for the generalized linear models(GLM)in the orthogonal time frequency space(OTFS)underwater acoustic(UWA)system.OTFS works in the delay-Doppler domain,where tim... This paper addresses sparse channels estimation problem for the generalized linear models(GLM)in the orthogonal time frequency space(OTFS)underwater acoustic(UWA)system.OTFS works in the delay-Doppler domain,where timevarying channels are characterized as delay-Doppler impulse responses.In fact,a typical doubly spread UWA channel is associated with several resolvable paths,which exhibits a structured sparsity in the delayDoppler domain.To leverage the structured sparsity of the doubly spread UWA channel,we develop a structured sparsity-based generalized approximated message passing(GAMP)algorithm for reliable channel estimation in quantized OTFS systems.The proposed algorithm has a lower computational complexity compared to the conventional Bayesian algorithm.In addition,the expectation maximum algorithm is employed to learn the sparsity ratio and the noise variance.Simulation and experimental results show that the proposed algorithm has superior performance and low computational complexity for quantized OTFS systems. 展开更多
关键词 OTFS doubly spread UWA channel delay-Doppler domain GAMP
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Pulsed electrolysis of carbon dioxide by large-scale solid oxide electrolytic cells for intermittent renewable energy storage 被引量:2
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作者 Anqi Wu Chaolei Li +5 位作者 Beibei Han Wu Liu yang zhang Svenja Hanson Wanbing Guan Subhash C.Singhal 《Carbon Energy》 SCIE CSCD 2023年第4期2-12,共11页
CO_(2) electrolysis with solid oxide electrolytic cells(SOECs)using intermittently available renewable energy has potential applications for carbon neutrality and energy storage.In this study,a pulsed current strategy... CO_(2) electrolysis with solid oxide electrolytic cells(SOECs)using intermittently available renewable energy has potential applications for carbon neutrality and energy storage.In this study,a pulsed current strategy is used to replicate intermittent energy availability,and the stability and conversion rate of the cyclic operation by a large-scale flat-tube SOEC are studied.One hundred cycles under pulsed current ranging from -100 to -300 mA/cm^(2) with a total operating time of about 800 h were carried out.The results show that after 100 cycles,the cell voltage attenuates by 0.041%/cycle in the high current stage of−300 mA/cm^(2),indicating that the lifetime of the cell can reach up to about 500 cycles.The total CO_(2) conversion rate reached 52%,which is close to the theoretical value of 54.3% at -300 mA/cm^(2),and the calculated efficiency approached 98.2%,assuming heat recycling.This study illustrates the significant advantages of SOEC in efficient electrochemical energy conversion,carbon emission mitigation,and seasonal energy storage. 展开更多
关键词 carbon dioxide cyclic electrolysis pulse current solid oxide electrolytic cells
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Calcitriol attenuates liver fibrosis through hepatitis C virus nonstructural protein 3-transactivated protein 1-mediated TGF β1/Smad3 and NF-κB signaling pathways 被引量:1
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作者 Liu Shi Li Zhou +13 位作者 Ming Han Yu zhang yang zhang Xiao-Xue Yuan Hong-Ping Lu Yun Wang Xue-Liang yang Chen Liu Jun Wang Pu Liang Shun-Ai Liu Xiao-Jing Liu Jun Cheng Shu-Mei Lin 《World Journal of Gastroenterology》 SCIE CAS 2023年第18期2798-2817,共20页
BACKGROUND Hepatic fibrosis is a serious condition,and the development of hepatic fibrosis can lead to a series of complications.However,the pathogenesis of hepatic fibrosis remains unclear,and effective therapy optio... BACKGROUND Hepatic fibrosis is a serious condition,and the development of hepatic fibrosis can lead to a series of complications.However,the pathogenesis of hepatic fibrosis remains unclear,and effective therapy options are still lacking.Our group identified hepatitis C virus nonstructural protein 3-transactivated protein 1(NS3TP1) by suppressive subtractive hybridization and bioinformatics analysis,but its role in diseases including hepatic fibrosis remains undefined.Therefore,additional studies on the function of NS3TP1 in hepatic fibrosis are urgently needed to provide new targets for treatment.AIM To elucidate the mechanism of NS3TP1 in hepatic fibrosis and the regulatory effects of calcitriol on NS3TP1.METHODS Twenty-four male C57BL/6 mice were randomized and separated into three groups,comprising the normal,fibrosis,and calcitriol treatment groups,and liver fibrosis was modeled by carbon tetrachloride(CCl4).To evaluate the level of hepatic fibrosis in every group,serological and pathological examinations of the liver were conducted.TGF-β1 was administered to boost the in vitro cultivation of LX-2 cells.NS3TP1,α-smooth muscle actin(α-SMA),collagen I,and collagen Ⅲ in every group were examined using a Western blot and real-time quantitative polymerase chain reaction.The activity of the transforming growth factor beta 1(TGFβ1)/Smad3 and NF-κB signaling pathways in each group of cells transfected with pcDNA-NS3TP1 or siRNA-NS3TP1 was detected.The statistical analysis of the data was performed using the Student’s t test.RESULTS NS3TP1 promoted the activation,proliferation,and differentiation of hepatic stellate cells(HSCs)and enhanced hepatic fibrosis via the TGFβ1/Smad3 and NF-κB signaling pathways,as evidenced by the presence of α-SMA,collagen I,collagen Ⅲ,p-smad3,and p-p65 in LX-2 cells,which were upregulated after NS3TP1 overexpression and downregulated after NS3TP1 interference.The proliferation of HSCs was lowered after NS3TP1 interference and elevated after NS3TP1 overexpression,as shown by the luciferase assay.NS3TP1 inhibited the apoptosis of HSCs.Moreover,both Smad3 and p65 could bind to NS3TP1,and p65 increased the promoter activity of NS3TP1,while NS3TP1 increased the promoter activity of TGFβ1 receptor I,as indicated by coimmunoprecipitation and luciferase assay results.Both in vivo and in vitro,treatment with calcitriol dramatically reduced the expression of NS3TP1.Calcitriol therapy-controlled HSCs activation,proliferation,and differentiation and substantially suppressed CCl4-induced hepatic fibrosis in mice.Furthermore,calcitriol modulated the activities of the above signaling pathways via downregulation of NS3TP1.CONCLUSION Our results suggest that calcitriol may be employed as an adjuvant therapy for hepatic fibrosis and that NS3TP1 is a unique,prospective therapeutic target in hepatic fibrosis. 展开更多
关键词 Nonstructural protein 3-transactivated protein 1 CALCITRIOL Liver fibrosis Hepatic stellate cells Mouse model TGFβ1/Smad3 NF-κB Signaling pathway
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