期刊文献+
共找到19,609篇文章
< 1 2 250 >
每页显示 20 50 100
Topology transformation of the zeolite catalysts to enhance electronic metal-support interactions and hydrogen spillover effects for hydrogenation of aromatic-rich oil to high-density aviation fuels
1
作者 Xiaoqi Zhang Kai Meng +10 位作者 He Liu Bernard Wiafe Biney Yiqiang Qi Kunyu Xu Jiang Wu Liying Xie Xiaoyu Li Yueliang Liu Kun Chen Zongxian Wang Aijun Guo 《Journal of Energy Chemistry》 2025年第7期1026-1037,共12页
Metal-support interactions and hydrogen spillover effects in heterogeneous catalysts play a crucial role in aromatic hydrogenation reactions;however,these effects are limited by the metal dispersion on the catalyst an... Metal-support interactions and hydrogen spillover effects in heterogeneous catalysts play a crucial role in aromatic hydrogenation reactions;however,these effects are limited by the metal dispersion on the catalyst and the number of acceptable H*receptors.This study prepares highly dispersed Ni nanoparticles(NPs)catalysts on a Beta substrate via precursor structure topology transformation.In contrast to traditional support materials,the coordination and electronic structure changes between the Ni NPs and the support were achieved,further optimizing the active interface sites and enhancing hydrogen activation and hydrogenation performance.Additionally,the-OH groups at the strong acid sites in zeolite effectively intensified the hydrogen spillover effect as receptors for H^(*)migration and anchoring,accelerating the hydrogenation rate of aromatic rings.Under solvent-free conditions,this catalyst was used for the hydrogenation reaction of aromatic-rich oils,directly producing a C_(8)-C_(14)branched cycloalkanes mixture with an aromatic conversion rate of>99%.The cycloalkanes mixture produced by this method features high density(0.92 g/mL)and a low freezing point(<-60℃),making it suitable for use as high-density aviation fuel or as an additive to enhance the volumetric heat value of conventional aviation fuels in practical applications. 展开更多
关键词 Metal-support interaction Hydrogen spillover ZEOLITE Aromatic-richoil high-density aviation fuels
在线阅读 下载PDF
Preparation and Characterization of Multilayered High-density Polyethylene with Tunable Crystalline Structure
2
作者 Yi-Jie Ma Jia-Wei Gong +4 位作者 Bin Chen Ying Zhang Gan-Ji Zhong Zhong-Ming Li Xue-Qin Gao 《Chinese Journal of Polymer Science》 2025年第9期1616-1628,I0011,共14页
In rotationally extruded fittings,high-density polyethylene(HDPE)pipes prepared using conventional processing methods often suffer from poor pressure resistance and low toughness.This study introduces an innovative ro... In rotationally extruded fittings,high-density polyethylene(HDPE)pipes prepared using conventional processing methods often suffer from poor pressure resistance and low toughness.This study introduces an innovative rotary shear system(RSS)to address these deficiencies through controlled mandrel rotation and cooling rates.We successfully prepared self-reinforced HDPE pipes with a three-layer structure combining spherical and shish-kebab crystals.Rotational processing aligned the molecular chains in the ring direction and formed shish-kebab crystals.As a result,the annular tensile strength of the rotationally processed three-layer shish-kebab structure(TSK)pipe increased from 26.7 MPa to 76.3 MPa,an enhancement of 185.8%.Notably,while maintaining excellent tensile strength(73.4 MPa),the elongation at break of the spherulite shishkebab spherulite(SKS)tubes was improved to 50.1%,as compared to 33.8%in the case of shish-kebab spherulite shish-kebab(KSK)tubes.This improvement can be attributed to the changes in the micro-morphology and polymer structure within the SKS tubes,specifically due to the formation of small-sized shish-kebab crystals and the low degrees of interlocking.In addition,2D-SAXS analysis revealed that KSK tubes have higher tensile strength due to smaller crystal sizes and larger shish dimensions,forming dense interlocking structures.In contrast,the SKS and TSK tubes had thicker amorphous regions and smaller shish sizes,resulting in reduced interlocking and mechanical performance. 展开更多
关键词 high-density polyethylene pipe SHISH-KEBAB Circumferential tensile strength Rotational shear Multilayer structure
原文传递
Application of high-density electrical resistivity tomography in backfilling effectiveness of quarries:A case study of Liuyao Village quarry in Huaibei City,Anhui Province
3
作者 XU Guangrui LIU Lijia HAN Jiangtao 《Global Geology》 2025年第4期231-239,共9页
Evaluation of backfilling effectiveness plays a crucial role in the geological environment management and restoration of abandoned open-pit quarries,providing a scientific basis for subsequent greening efforts.Backfil... Evaluation of backfilling effectiveness plays a crucial role in the geological environment management and restoration of abandoned open-pit quarries,providing a scientific basis for subsequent greening efforts.Backfill soil,predominantly composed of silty clay,demonstrates high water retention capacity and elevated moisture content,leading to a pronounced resistivity contrast with the bedrock exposed by quarrying activities.To investigate the distribution of backfill soil subsurface and assess backfilling effectiveness in the study area,this study conducted a comprehensive geophysical investigation utilizing the high-density electrical resistivity tomography(ERT).A total of 19 ERT survey lines were deployed across three distinct areas in Liuyao Village,Huaibei City,Anhui Province,China.The inversion results,derived from both two-dimensional(2D)and three-dimensional(3D),reveal distinct electrical properties of the subsurface materials:the backfill soil layer shows low resistivity features,the fill stone layer exhibits medium to high resistivity,and the bedrock shows the highest resistivity.The 2D inversion results,from the data measured using the Wenner array effectively capture the spatial distribution and structural features of the backfill soil layer.The findings indicate a gradual east-west thinning of the clay layer within the quarry.Furthermore,the northern pit area exhibits a uniform distribution of backfill soil layer,indicative of effective backfilling operations.In contrast,the southern pit area lacks a well-defined clay layer,suggesting suboptimal backfilling effectiveness. 展开更多
关键词 high-density electrical resistivity tomography Wenner array backfilling effectiveness backfill soil
在线阅读 下载PDF
3D laser structuring of supermetalphobic microstructures inside elastomer for multilayer high-density interconnect soft electronics
4
作者 Chengjun Zhang Qing Yang +5 位作者 Haoyu Li Zexiang Luo Yu Lu Jialiang Zhang Cheng Li Feng Chen 《International Journal of Extreme Manufacturing》 2025年第3期337-348,共12页
High-density interconnect(HDI)soft electronics that can integrate multiple individual functions into one miniaturized monolithic system is promising for applications related to smart healthcare,soft robotics,and human... High-density interconnect(HDI)soft electronics that can integrate multiple individual functions into one miniaturized monolithic system is promising for applications related to smart healthcare,soft robotics,and human-machine interactions.However,despite the recent advances,the development of three-dimensional(3D)soft electronics with both high resolution and high integration is still challenging because of the lack of efficient manufacturing methods to guarantee interlayer alignment of the high-density vias and reliable interlayer electrical conductivity.Here,an advanced 3D laser printing pathway,based on femtosecond laser direct writing(FLDW),is demonstrated for preparing liquid metal(LM)-based any layer HDI soft electronics.FLDW technology,with the characteristics of high spatial resolution and high precision,allows the maskless fabrication of high-resolution embedded LM microchannels and high-density vertical interconnect accesses for 3D integrated circuits.High-aspect-ratio blind/through LM microstructures are formed inside the elastomer due to the supermetalphobicity induced during laser ablation.The LM-based HDI circuit featuring high resolution(~1.5μm)and high integration(10-layer electrical interconnection)is achieved for customized soft electronics,including various customized multilayer passive electric components,soft multilayer circuit,and cross-scale multimode sensors.The 3D laser printing method provides a versatile approach for developing chip-level soft electronics. 展开更多
关键词 3D soft electronics liquid metal high-density interconnection femtosecond laser direct writing supermetalphobicity
在线阅读 下载PDF
Enhancing strength at elevated temperatures via dynamic high-density mobile dislocations in Mg alloys
5
作者 Mingyu Fan Ye Cui +13 位作者 Xin Zhou Junming Chen Yang Zhang Lixin Sun Jamieson Brechtl Daqing Fang Qian Li Qingqing Ding Hongbin Bei Peter K.Liaw Yanzhuo Xue Xun-Li Wang Yang Lu Zhongwu Zhang 《Journal of Magnesium and Alloys》 2025年第8期3768-3783,共16页
Dislocation strengthening,as one of the methods to simultaneously enhance the room temperature strength and ductility of alloys,does not achieve the desired strengthening and plasticity effect during elevated-temperat... Dislocation strengthening,as one of the methods to simultaneously enhance the room temperature strength and ductility of alloys,does not achieve the desired strengthening and plasticity effect during elevated-temperature deformation.Here,we report a novel strategy to boost the dislocation multiplication and accumulation during deformation at elevated temperatures through dynamic strain aging(DSA).With the introduction of the rare-earth element Ho in Mg-Y-Zn alloy,Ho atoms diffuse toward dislocations during deformation at elevated temperatures,provoking the DSA effect,which increases the dislocation density significantly via the interactions of mobile dislocations and Ho atoms.The resulting alloy achieves a great enhancement of dislocation hardening and obtains the dual benefits of high strength and good ductility simultaneously at high homologous temperatures.The present work provides an effective strategy to enhancing the strength and ductility for elevated-temperature materials. 展开更多
关键词 Mg-Y-Zn alloy Ho addition high-density mobile dislocations Dynamic strain aging(DSA) Elevated-temperature strength
在线阅读 下载PDF
Association between uric acid to high-density lipoprotein ratio and mental health symptoms in people with type 2 diabetes
6
作者 Hui Xu Dong-Juan He +6 位作者 Cheng Luo Xian-Mei Yu Cheng-Zheng Duan Da Sun De-Jun Wu Xiao-Qiang Mao Wei-Feng Jiang 《World Journal of Diabetes》 2025年第10期249-260,共12页
BACKGROUND The association between the uric acid-to-high-density lipoprotein cholesterol ratio(UHR)and mental health among individuals with type 2 diabetes mellitus(T2DM)has not been thoroughly investigated.AIM To exa... BACKGROUND The association between the uric acid-to-high-density lipoprotein cholesterol ratio(UHR)and mental health among individuals with type 2 diabetes mellitus(T2DM)has not been thoroughly investigated.AIM To examine the link between UHR and symptoms of depression and anxiety in patients with T2DM.METHODS A cross-sectional analysis was carried out from March 2023 to April 2024,involving participants diagnosed with T2DM.Data on sociodemographic characteristics,clinical parameters,and UHR values were systematically gathered.The Self-Rating Depression Scale(SDS)and Self-Rating Anxiety Scale(SAS)were utilized to evaluate depressive and anxiety symptoms,respectively.To assess the relationships between UHR and SDS/SAS scores,linear regression models were employed,incorporating adjustments for potential confounding variables.Additionally,smooth curve fitting and threshold effect analyses were conducted to explore potential nonlinear relationships.RESULTS A total of 285 patients with T2DM were included.Initial univariate analysis demonstrated a significant positive correlation between elevated UHR levels and higher SDS and SAS scores.Multivariate regression analysis revealed that a one-unit rise in UHR was associated with a 1.13-point increase in SDS scores(95%CI:0.69-1.58)and a 0.57-point increase in SAS scores(95%CI:0.20-0.93).After controlling for confounders,UHR remained positively correlated with SDS(β=1.55,95%CI:0.57-2.53)and SAS(β=0.72,95%CI:0.35-1.09).Nonlinear analysis identified critical thresholds at UHR values of 5.02 for SDS and 4.00 for SAS,beyond which the relationships between UHR and psychological symptom scores became markedly stronger(P<0.05).CONCLUSION Higher UHR levels are significantly linked to exacerbated depressive and anxiety symptoms in patients with T2DM.These results indicate that UHR may function as a promising biomarker to identify individuals at greater risk of mental health complications within this population. 展开更多
关键词 ANXIETY DEPRESSION Type 2 diabetes mellitus Uric acid high-density lipoprotein cholesterol Uric acid-to-highdensity lipoprotein cholesterol ratio
暂未订购
Construction of a high-density genetic map to explore the genetic regulation of erucic acid, oleic acid, and linolenic acid contents in Brassica juncea
7
作者 Wei Yan Jinze Zhang +5 位作者 Yingfen Jiang Kunjiang Yu Qian Wang Xu Yang Lijing Xiao Entang Tian 《Journal of Integrative Agriculture》 2025年第6期2171-2189,共19页
Rapeseed mustard(Brassica juncea L.) is the third most important oilseed crop in the world, but the geneticmechanism underlying its massive phenotypic variation remains largely unexplored. In this study, specific leng... Rapeseed mustard(Brassica juncea L.) is the third most important oilseed crop in the world, but the geneticmechanism underlying its massive phenotypic variation remains largely unexplored. In this study, specific length amplified fragment sequencing(SLAF-Seq) was used to resequence a population comprising 197 F8recombinantinbred lines(RILs) derived from a cross between vegetable-type Qichi881 and oilseed-type YufengZC of B. juncea. In total, 438,895 high-quality SLAFs were discovered, 47,644 of which were polymorphic, and 3,887 of the polymorphic markers met the requirements for genetic map construction. The final map included 3,887 markers on 18 linkage groups and was 1,830.23 centiMorgan(cM) in length, with an average distance of 0.47 cM between adjacent markers. Using the newly constructed high-density genetic map, a total of 53 QTLs for erucicacid(EA), oleic acid(OA), and linolenic acid(LNA) were detected and integrated into eight consensus QTLswith two for each of these traits. For each of these three traits, two candidate genes were cloned and sequence analysis indicated colocalization with their respective consensus QTLs. The co-dominant allele-specific markers for Bju.FAD3.A03 and Bju.FAD3.B07 were developed and showed co-localization with their consensus QTLs andco-segregation with LNA content, further supporting the results of QTL mapping and bioinformatic analysis. Theexpression levels of the cloned homologous genes were also determined, and the genes were tightly correlatedwith the EA, OA and LNA contents of different lines. The results of this study will facilitate the improvement offatty acid traits and molecular breeding of B. juncea. Further uses of the high-density genetic map created in this study are also discussed. 展开更多
关键词 Brassica juncea high-density genetic map Bju.FAE1 Bju.FAD2 Bju.FAD3
在线阅读 下载PDF
Prediction of Self-Care Behaviors in Patients Using High-Density Surface Electromyography Signals and an Improved Whale Optimization Algorithm-Based LSTM Model
8
作者 Shuai Huang Dan Liu +4 位作者 Youfa Fu Jiadui Chen Ling He Jing Yan Di Yang 《Journal of Bionic Engineering》 2025年第4期1963-1984,共22页
Stroke survivors often face significant challenges when performing daily self-care activities due to upper limb motor impairments.Traditional surface electromyography(sEMG)analysis typically focuses on isolated hand p... Stroke survivors often face significant challenges when performing daily self-care activities due to upper limb motor impairments.Traditional surface electromyography(sEMG)analysis typically focuses on isolated hand postures,overlooking the complexity of object-interactive behaviors that are crucial for promoting patient independence.This study introduces a novel framework that combines high-density sEMG(HD-sEMG)signals with an improved Whale Optimization Algorithm(IWOA)-optimized Long Short-Term Memory(LSTM)network to address this limitation.The key contributions of this work include:(1)the creation of a specialized HD-sEMG dataset that captures nine continuous self-care behaviors,along with time and posture markers,to better reflect real-world patient interactions;(2)the development of a multi-channel feature fusion module based on Pascal’s theorem,which enables efficient signal segmentation and spatial–temporal feature extraction;and(3)the enhancement of the IWOA algorithm,which integrates optimal point set initialization,a diversity-driven pooling mechanism,and cosine-based differential evolution to optimize LSTM hyperparameters,thereby improving convergence and global search capabilities.Experimental results demonstrate superior performance,achieving 99.58%accuracy in self-care behavior recognition and 86.19%accuracy for 17 continuous gestures on the Ninapro db2 benchmark.The framework operates with low latency,meeting the real-time requirements for assistive devices.By enabling precise,context-aware recognition of daily activities,this work advances personalized rehabilitation technologies,empowering stroke patients to regain autonomy in self-care tasks.The proposed methodology offers a robust,scalable solution for clinical applications,bridging the gap between laboratory-based gesture recognition and practical,patient-centered care. 展开更多
关键词 Self-care behaviors high-density surface electromyography(HD-sEMG) Long Short-Term Memory(LSTM)network Multi-channel feature fusion
在线阅读 下载PDF
质子FLASH照射对人肝细胞及肝癌细胞辐射损伤比较
9
作者 汪越 隋丽 +3 位作者 王巧娟 刘建成 苏鹏 黄志豪 《中华放射医学与防护杂志》 北大核心 2025年第11期1107-1114,共8页
目的研究质子FLASH与常规剂量率(CONV)照射下对人肝细胞WRL68与人肝癌细胞HepG2的差异作用。方法使用100 MeV强流质子回旋加速器对WRL68与HepG2细胞分别开展常规剂量率(0.8 Gy/min)与超高剂量率(40 Gy/s)的质子4 Gy照射,照射后在不同时... 目的研究质子FLASH与常规剂量率(CONV)照射下对人肝细胞WRL68与人肝癌细胞HepG2的差异作用。方法使用100 MeV强流质子回旋加速器对WRL68与HepG2细胞分别开展常规剂量率(0.8 Gy/min)与超高剂量率(40 Gy/s)的质子4 Gy照射,照射后在不同时间点检测细胞增殖、凋亡与周期阻滞变化,并通过转录组测序对不同细胞的基因表达谱变化进行分析。结果对于人肝细胞,相较于常规照射,质子FLASH照射提高了细胞增殖活力(t=10.18~16.67,P<0.05),降低了细胞凋亡率(t=3.21~8.30,P<0.05),同一时间点细胞G2期阻滞占比有所降低(t=34.08~65.16,P<0.05)。对于肝癌细胞,相较于常规照射,质子FLASH照射显著抑制了细胞增殖(t=2.57~9.39,P<0.05),细胞凋亡水平有所提升(t=3.25~66.70,P<0.05),周期变化同样集中于G2期阻滞(t=10.87~27.47,P<0.05)。转录组测序结果显示对于WRL68细胞,在FLASH组与CONV组间共发现906个差异表达基因;对于HepG2细胞,在FLASH组与CONV组间共发现1243个差异表达基因,差异表达基因的基因本体(GO)与京都基因与基因组百科全书(KEGG)分析表明,细胞黏附、氧效应等可能是FLASH-RT的重要微观作用机制。结论质子FLASH照射下人肝细胞放射损伤显著降低,而肝癌细胞损伤加重,相关差异表达基因涉及了多类放射生物学功能通路。 展开更多
关键词 flash照射 质子 肝脏 放射损伤 肝癌
原文传递
质子FLASH照射和常规照射对肾癌细胞周期和死亡的影响
10
作者 张俊 张思倩 +3 位作者 王巧娟 隋丽 张永胜 曹志飞 《中华放射医学与防护杂志》 北大核心 2025年第11期1100-1106,共7页
目的探究质子FLASH照射(FLASH-IR)和常规照射(CONV-IR)对肾癌细胞周期、细胞凋亡和细胞焦亡的影响。方法分别给予人肾癌细胞株769-P 8 Gy质子照射,FLASH-IR的剂量率为40 Gy/s,CONV-IR的剂量率为0.4 Gy/s,对照(Ctrl)组不照射。照射后24 ... 目的探究质子FLASH照射(FLASH-IR)和常规照射(CONV-IR)对肾癌细胞周期、细胞凋亡和细胞焦亡的影响。方法分别给予人肾癌细胞株769-P 8 Gy质子照射,FLASH-IR的剂量率为40 Gy/s,CONV-IR的剂量率为0.4 Gy/s,对照(Ctrl)组不照射。照射后24 h收集细胞,采用流式细胞术检测细胞周期变化。采用实时荧光定量聚合酶链式反应(RT-qPCR)和蛋白免疫印迹实验,检测肾癌细胞周期、凋亡和焦亡信号通路相关基因与蛋白表达情况。结果质子FLASH-IR使G_(0)/G_(1)期肾癌细胞比例增加[FLASH-IR组vs.Ctrl组:(67.01±0.44)%vs.(38.68±0.63)%,t=-63.99,P<0.05],而CONV-IR使G_(2)/M期肾癌细胞比例增加[CONV-IR组vs.Ctrl组:(56.65±1.52)%vs.(23.67±0.51)%,t=-29.17,P<0.05]。质子FLASH-IR和CONV-IR均导致肾癌细胞发生凋亡(t_(FLASH)=-16.24~-5.01,P<0.05;t_(CONV)=-20.08~6.11,P<0.05)并且CONV-IR激活P53/P21通路(t=-16.86~-9.74,P<0.05)。质子FLASH-IR和CONV-IR同样诱导肾癌细胞发生焦亡(t_(FLASH)=-23.36~20.18,P<0.05;t_(CONV)=-41.62~13.95,P<0.05),且与CONV-IR相比,质子FLASH-IR使肾癌细胞发生焦亡的程度更高(FLASH-IR组vs.CONV-IR:0.96±0.01 vs.0.68±0.44,t=-10.46,P<0.05)。结论质子FLASH照射和常规照射均会影响肾癌细胞周期变化,促进细胞凋亡和焦亡,但两者存在差异,其机制有待进一步探索。质子FLASH照射在肾癌治疗中有潜在应用价值。 展开更多
关键词 flash照射 常规照射 细胞周期 细胞凋亡 细胞焦亡
原文传递
X射线FLASH放射治疗的射线来源、计量与防护研究现状
11
作者 吴岱 羊奕伟 +3 位作者 张毅 唐瑛鸿 胡旭林 王青青 《中华放射医学与防护杂志》 北大核心 2025年第11期1041-1046,共6页
国际上诸多研究表明,电子线、X射线、质子和重离子都可以用于超高剂量率放疗,其中MV级X射线超高剂量率放疗具有广阔的临床前景。中国工程物理研究院应用电子学研究所基于其在强脉冲射线源领域多年的研究积累,在全球率先解决了兆伏级超... 国际上诸多研究表明,电子线、X射线、质子和重离子都可以用于超高剂量率放疗,其中MV级X射线超高剂量率放疗具有广阔的临床前景。中国工程物理研究院应用电子学研究所基于其在强脉冲射线源领域多年的研究积累,在全球率先解决了兆伏级超高剂量率X射线的产生和计量(剂量测量)难题,助力中国走在相关领域的国际前列。本文主要介绍超高剂量率X射线产生、计量和防护领域的发展历程、现状和未来趋势。这些数据将为研究人员在临床和临床前试验、设备研发和标准制定等多个方面提供可靠的参考,以便实现更精确、更可靠的超高剂量率兆伏级X射线产生和计量,期望对超高剂量率放疗技术的深入研究和临床应用提供支持。 展开更多
关键词 flash放射治疗 X射线 射线源 剂量学
原文传递
双源CT Flash扫描联合70 kV在儿童肺炎复查的可行性研究
12
作者 张涛 曹永佩 李正正 《中国医学计算机成像杂志》 北大核心 2025年第5期732-737,共6页
目的:探讨双源CT Flash扫描联合70 kV在儿童肺炎复查中的可行性。方法:前瞻性收集2024年1—7月因肺炎就诊我院,并完成前后两次CT扫描的30例患者,其中男14例,女16例,平均年龄(7.3±3.5)岁(5个月~11.5岁),体重指数(BMI)为(15.45±... 目的:探讨双源CT Flash扫描联合70 kV在儿童肺炎复查中的可行性。方法:前瞻性收集2024年1—7月因肺炎就诊我院,并完成前后两次CT扫描的30例患者,其中男14例,女16例,平均年龄(7.3±3.5)岁(5个月~11.5岁),体重指数(BMI)为(15.45±2.62)kg/m^(2)。根据研究方案,均采用Flash模式扫描,首次检查使用80 kV管电压,复查使用70 kV管电压,其余参数相同。比较前后两次CT扫描图像质量、辐射剂量。结果:与首次检查相比,复查的辐射剂量指标CT剂量指数(CTDIvol)、剂量长度乘积(DLP)和全身有效剂量(ED)分别降低了40.38%[(0.31±0.11)mGy vs(0.52±0.20)mGy]、40.74%[(8.67±3.76)mGy·cm vs(14.63±7.18)mGy·cm]和40.91%[(0.13±0.05)mSv vs(0.22±0.10)mSv],差异有统计学意义(均P<0.001);与首次检查图像质量相比,复查图像的背景噪声值增高,信噪比(SNR)值、对比度噪声比(CNR)值分别下降21.14%、13.42%,差异具有统计学意义(均P<0.05);2名医师对两组图像的主观评分一致性高(Kappa=0.72~0.879),两组图像的肺窗和纵隔窗图像质量评分均存在差异(P<0.001),以肺窗图像为判断标准,首次检查图像质量中位评分为5分(4分,5分),复查图像质量的中位评分为4分(3分,5分),所有图像质量均满足诊断需求。结论:70 kV联合双源CT Flash扫描在儿童肺炎复查中具有很好的可行性,图像质量可以满足临床诊断和评价治疗效果需求,且辐射剂量显著降低,值得临床推广使用。 展开更多
关键词 低管电压 双源CT flash模式 低辐射剂量 儿童肺炎
暂未订购
DSP片上Flash测试系统设计与实现
13
作者 王涛 于鹏 钱昀莹 《电子技术应用》 2025年第2期41-45,共5页
在DSP芯片的可靠性筛选考核试验中,片上Flash擦写耐久和数据保持测试是最重要的试验之一。针对内建自测试和外部自动化机台测试的局限性,提出了一种DSP片上Flash测试系统的设计与实现方法。在分析了Flash故障类型和测试算法的基础上,给... 在DSP芯片的可靠性筛选考核试验中,片上Flash擦写耐久和数据保持测试是最重要的试验之一。针对内建自测试和外部自动化机台测试的局限性,提出了一种DSP片上Flash测试系统的设计与实现方法。在分析了Flash故障类型和测试算法的基础上,给出了硬件原理图和软件实现流程,并搭建了实物平台进行效果评估。测试结果表明:该系统可实现多工位DSP片上Flash自动化测试,无需人工参与。同时工作状态可实时显示,测试过程中的数据和结果自动保存在外部存储器中,便于后期进行测试结果统计分析。 展开更多
关键词 片上flash 擦写耐久 数据保持 测试系统
在线阅读 下载PDF
基于Flash ActionScript语言的凸轮机构运动规律研究
14
作者 刘先梅 张明存 《白城师范学院学报》 2025年第2期51-57,共7页
基于Flash ActionScript语言开发了一套参数驱动的平面凸轮机构运动仿真系统,通过设计不同的虚拟实验让使用者了解平面凸轮机构的组成、工作原理、特点及其运动形式.该系统可实现用户注册、密码登陆、凸轮从动件运动规律的实验设计等不... 基于Flash ActionScript语言开发了一套参数驱动的平面凸轮机构运动仿真系统,通过设计不同的虚拟实验让使用者了解平面凸轮机构的组成、工作原理、特点及其运动形式.该系统可实现用户注册、密码登陆、凸轮从动件运动规律的实验设计等不同功能,通过参数化输入时的运动分析与仿真,自动生成凸轮轮廓及不同运动规律下的升程、速度、位移三个线图.研究结果表明,基于Flash ActionScript的凸轮机构运动规律的系统设计,实现了凸轮从动件运动规律的分析. 展开更多
关键词 flash ActionScript语言 平面凸轮机构 运动分析与仿真 参数化
在线阅读 下载PDF
T-Flash学习软件研发及其在病理学实验课中的U-应用效果研究
15
作者 罗康华 刘昕 +2 位作者 吴亚东 刘嘉琪 蒋催蓉 《黔南民族医专学报》 2025年第2期230-233,共4页
目的:本研究旨在解决基础医学病理学实验课学习效果不佳的问题,通过研发手机端T-Flash学习软件,结合智能手机的自主、交互、便携、实时等特性,创新实验课学习方式,以激发学生的学习兴趣,提高学习效果。方法:本研究以Tips(知识小贴士)、T... 目的:本研究旨在解决基础医学病理学实验课学习效果不佳的问题,通过研发手机端T-Flash学习软件,结合智能手机的自主、交互、便携、实时等特性,创新实验课学习方式,以激发学生的学习兴趣,提高学习效果。方法:本研究以Tips(知识小贴士)、Training(训练)和Test(考核)(简称3T)为设计理念,采用消消乐Flash游戏为载体,建立病理标本图片、知识Tips等素材库;在Unity平台制作试用版软件,选取典型病理器官标本和组织切片标本图片制作游戏图标,在游戏载入、返场及点击图标时设计知识Tips闪现滚动;设置闯关关卡、竞技场及积分榜,对在线学习及互动情况进行实时监控和测评;开发基于AI技术的实验小助手,通过病理实验课考试和问卷调查进行软件应用效果评价。结果:设计并开发了T-Flash学习软件v1.0版申请软件著作权获授权。实验组的标本考试成绩与理论考试成绩较对照组显著提高(P<0.05)。T-Flash v1.0版能有效辅助学习,激发学习兴趣,提高学习成绩。50名学生的问卷调查反馈积极,软件受到学生的欢迎。结论:T-Flash消消乐学习软件在基础医学病理学实验课中的创新应用取得了显著成效,证明了其作为新型学习工具的可行性和有效性。该软件不仅能提升学生的学习效果和兴趣,还具有推广到其他学科领域的潜力。本研究为医学教育领域的学习模式创新提供了有益的探索和借鉴。 展开更多
关键词 T-flash学习软件 病理学 实验课 创新教学 flash游戏
在线阅读 下载PDF
Kinetic-Thermodynamic Promotion Engineering toward High-Density Hierarchical and Zn-Doping Activity-Enhancing ZnNiO@CF for High-Capacity Desalination 被引量:2
16
作者 Jie Ma Siyang Xing +2 位作者 Yabo Wang Jinhu Yang Fei Yu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第8期35-50,共16页
Despite the promising potential of transition metal oxides(TMOs)as capacitive deionization(CDI)electrodes,the actual capacity of TMOs electrodes for sodium storage is significantly lower than the theoretical capacity,... Despite the promising potential of transition metal oxides(TMOs)as capacitive deionization(CDI)electrodes,the actual capacity of TMOs electrodes for sodium storage is significantly lower than the theoretical capacity,posing a major obstacle.Herein,we prepared the kinetically favorable Zn_(x)Ni_(1−x)O electrode in situ growth on carbon felt(Zn_(x)Ni_(1−x)O@CF)through constraining the rate of OH^(−)generation in the hydrothermal method.Zn_(x)Ni_(1−x)O@CF exhibited a high-density hierarchical nanosheet structure with three-dimensional open pores,benefitting the ion transport/electron transfer.And tuning the moderate amount of redox-inert Zn-doping can enhance surface electroactive sites,actual activity of redox-active Ni species,and lower adsorption energy,promoting the adsorption kinetic and thermodynamic of the Zn_(0.2)Ni_(0.8)O@CF.Benefitting from the kinetic-thermodynamic facilitation mechanism,Zn_(0.2)Ni_(0.8)O@CF achieved ultrahigh desalination capacity(128.9 mgNaCl g^(-1)),ultra-low energy consumption(0.164 kW h kgNaCl^(-1)),high salt removal rate(1.21 mgNaCl g^(-1) min^(-1)),and good cyclability.The thermodynamic facilitation and Na^(+)intercalation mechanism of Zn_(0.2)Ni_(0.8)O@CF are identified by the density functional theory calculations and electrochemical quartz crystal microbalance with dissipation monitoring,respectively.This research provides new insights into controlling electrochemically favorable morphology and demonstrates that Zn-doping,which is redox-inert,is essential for enhancing the electrochemical performance of CDI electrodes. 展开更多
关键词 Zinc-nickel metal oxide high-density hierarchical Capacitive deionization Zinc-doping
在线阅读 下载PDF
Fine grains with high-density annealing twins and precipitates inducing favorable strength and excellent plasticity in laser powder b e d fusion-fabricate d Inconel 718 via deep cryogenic and heat treatments 被引量:3
17
作者 Bo Liu Jiayu Xu +5 位作者 Yubi Gao Yong Hu Xiaokang Yang Yutian Ding Dong Zhang Sujun Lu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2024年第20期28-48,共21页
Tailoring high-density annealing twins in laser powder bed fusion(LPBF)-fabricated alloys based on their intrinsic residual stress requires high annealing temperatures and/or long-term annealing,result-ing in the abno... Tailoring high-density annealing twins in laser powder bed fusion(LPBF)-fabricated alloys based on their intrinsic residual stress requires high annealing temperatures and/or long-term annealing,result-ing in the abnormal growth of large recrystallized grains,which is detrimental to mechanical properties.This work proposes a new strategy for achieving a favorable strength-plasticity synergy of the LPBF-fabricated Inconel 718 superalloy by performing a deep cryogenic treatment(DCT)with the subsequent heat treatment(including annealing and double aging)to tailor fine grains with“high-density annealing twins+precipitates”architectures and compares the obtained material with an alloy subjected to a direct heat treatment without a prior DCT.The obtained results reveal that the additional internal stress gen-erated during DCT increases the stored energy and dislocation density,which provide a sufficient driving force for activating high-density annealing twin boundaries(63.2%)with fine grains(31.6μm)within a short annealing time.The more homogeneous tailored microstructure with the“finer grains+high-density twins+precipitates”architectures decreases the mean free path of slipping dislocations,pro-moting intensive interactions with dislocations and inducing a strong strain hardening effect.The mul-tiple deformation modes of stacking faults coupled with Lomer-Cottrell locks,thin primary deformation twins,and secondary twins activated during tensile loading,sustaining a strong work hardening ability and delaying the plastic instability,which exhibits a high strength(yield strength of 1088 MPa and tensile strength of 1369 MPa)and excellent plasticity(elongation of 30%).This work not only describes a fea-sible method for simultaneously enhancing the strength and plasticity in additively manufactured(AM)alloys but also provides new insights into increasing the fraction of twins at a small grain size to improve the grain boundary-related properties without destroying the AM alloy shape. 展开更多
关键词 Laser powder bed fusion Deep cryogenic treatment Stored energy high-density annealing twins Work hardening
原文传递
Tandem hydroalkylation and deoxygenation of lignin-derived phenolics to synthesize high-density fuels 被引量:1
18
作者 Rui Yu Zhensheng Shen +6 位作者 Yanan Liu Chengxiang Shi Juncong Qu Lun Pan Zhenfeng Huang Xiangwen Zhan g Ji-Jun Zou 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第2期104-109,共6页
Lignin is the most abundant naturally phenolic biomass,and the synthesis of high-performance renewable fuel from lignin has attracted significant attention.We propose the efficient synthesis of high-density fuels usin... Lignin is the most abundant naturally phenolic biomass,and the synthesis of high-performance renewable fuel from lignin has attracted significant attention.We propose the efficient synthesis of high-density fuels using simulated lignin cracked oil in tandem with hydroalkylation and deoxygenation reactions.First,we investigated the reaction pathway for the hydroalkylation of phenol,which competes with the hydrodeoxygenation form cyclohexane.And then,we investigated the effects of metal catalyst types,the loading amount of metallic,acid dosage,and reactant ratio on the reaction results.The phenol hydroalkylation and hydrodeoxygenation were balanced when 180℃ and 5 MPa H_(2)with the alkanes yield of 95%.By extending the substrate to other lignin-derived phenolics and simulated lignin cracked oil,we obtained the polycyclic alkane fuel with high density of 0.918 g·ml^(-1)and calorific value of41.2 MJ·L^(-1).Besides,the fuel has good low-temperature properties(viscosity of 9.3 mm^(2)·s^(-1)at 20℃ and freezing point below-55℃),which is expected to be used as jet fuel.This work provides a promising way for the easy and green production of high-density fuel directly from real lignin oil. 展开更多
关键词 high-density fuel BIOFUEL Hydrogenation ALKYLATION Lignin Phenolics
在线阅读 下载PDF
Low Stress TSV Arrays for High-Density Interconnection 被引量:3
19
作者 Binbin Jiao Jingping Qiao +8 位作者 Shiqi Jia Ruiwen Liu Xueyong Wei Shichang Yun Yanmei Kong Yuxin Ye Xiangbin Du Lihang Yu Bo Cong 《Engineering》 SCIE EI CAS CSCD 2024年第7期201-208,共8页
In three-dimensional(3D)stacking,the thermal stress of through-silicon via(TSV)has a significant influence on chip performance and reliability,and this problem is exacerbated in high-density TSV arrays.In this study,a... In three-dimensional(3D)stacking,the thermal stress of through-silicon via(TSV)has a significant influence on chip performance and reliability,and this problem is exacerbated in high-density TSV arrays.In this study,a novel hollow tungsten TSV(W-TSV)is presented and developed.The hollow structure provides space for the release of thermal stress.Simulation results showed that the hollow W-TSV structure can release 60.3%of thermal stress within the top 2 lm from the surface,and thermal stress can be decreased to less than 20 MPa in the radial area of 3 lm.The ultra-high-density(1600 TSV∙mm2)TSV array with a size of 640×512,a pitch of 25 lm,and an aspect ratio of 20.3 was fabricated,and the test results demonstrated that the proposed TSV has excellent electrical and reliability performances.The average resistance of the TSV was 1.21 X.The leakage current was 643 pA and the breakdown voltage was greater than 100 V.The resistance change is less than 2%after 100 temperature cycles from40 to 125℃.Raman spectroscopy showed that the maximum stress on the wafer surface caused by the hollow W-TSV was 31.02 MPa,which means that there was no keep-out zone(KOZ)caused by the TSV array.These results indicate that this structure has great potential for applications in large-array photodetectors and 3D integrated circuits. 展开更多
关键词 Thermal stress Through-silicon via(TSV)high-density integration
在线阅读 下载PDF
Serum cystatin C,monocyte/high-density lipoprotein-C ratio,and uric acid for the diagnosis of coronary heart disease and heart failure 被引量:2
20
作者 Ming Li Da-Hao Yuan +2 位作者 Zhi Yang Teng-Xiang Luw Xiao-Biao Zou 《World Journal of Clinical Cases》 SCIE 2024年第18期3461-3467,共7页
BACKGROUND Coronary heart disease(CHD)and heart failure(HF)are the major causes of morbidity and mortality worldwide.Early and accurate diagnoses of CHD and HF are essential for optimal management and prognosis.Howeve... BACKGROUND Coronary heart disease(CHD)and heart failure(HF)are the major causes of morbidity and mortality worldwide.Early and accurate diagnoses of CHD and HF are essential for optimal management and prognosis.However,conventional diagnostic methods such as electrocardiography,echocardiography,and cardiac biomarkers have certain limitations,such as low sensitivity,specificity,availability,and cost-effectiveness.Therefore,there is a need for simple,noninvasive,and reliable biomarkers to diagnose CHD and HF.AIM To investigate serum cystatin C(Cys-C),monocyte/high-density lipoprotein cholesterol ratio(MHR),and uric acid(UA)diagnostic values for CHD and HF.METHODS We enrolled 80 patients with suspected CHD or HF who were admitted to our hospital between July 2022 and July 2023.The patients were divided into CHD(n=20),HF(n=20),CHD+HF(n=20),and control groups(n=20).The serum levels of Cys-C,MHR,and UA were measured using immunonephelometry and an enzymatic method,respectively,and the diagnostic values for CHD and HF were evaluated using receiver operating characteristic(ROC)curve analysis.RESULTS Serum levels of Cys-C,MHR,and UA were significantly higher in the CHD,HF,and CHD+HF groups than those in the control group.The serum levels of Cys-C,MHR,and UA were significantly higher in the CHD+HF group than those in the CHD or HF group.The ROC curve analysis showed that serum Cys-C,MHR,and UA had good diagnostic performance for CHD and HF,with areas under the curve ranging from 0.78 to 0.93.The optimal cutoff values of serum Cys-C,MHR,and UA for diagnosing CHD,HF,and CHD+HF were 1.2 mg/L,0.9×10^(9),and 389μmol/L;1.4 mg/L,1.0×10^(9),and 449μmol/L;and 1.6 mg/L,1.1×10^(9),and 508μmol/L,respectively.CONCLUSION Serum Cys-C,MHR,and UA are useful biomarkers for diagnosing CHD and HF,and CHD+HF.These can provide information for decision-making and risk stratification in patients with CHD and HF. 展开更多
关键词 Serum cystatin C Monocyte/high-density lipoprotein-C ratio Uric acid Coronary heart disease Heart failure Risk stratification
暂未订购
上一页 1 2 250 下一页 到第
使用帮助 返回顶部