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Evaluating the use of three-dimensional reconstruction visualization technology for precise laparoscopic resection in gastroesophageal junction cancer
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作者 dan guo Xiao-Yan Zhu +2 位作者 Shuai Han Yu-Shu Liu Da-Peng Cui 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第5期1311-1319,共9页
BACKGROUND Laparoscopic gastrectomy for esophagogastric junction(EGJ)carcinoma enables the removal of the carcinoma at the junction between the stomach and esophagus while preserving the gastric function,thereby provi... BACKGROUND Laparoscopic gastrectomy for esophagogastric junction(EGJ)carcinoma enables the removal of the carcinoma at the junction between the stomach and esophagus while preserving the gastric function,thereby providing patients with better treatment outcomes and quality of life.Nonetheless,this surgical technique also presents some challenges and limitations.Therefore,three-dimensional reconstruction visualization technology(3D RVT)has been introduced into the procedure,providing doctors with more comprehensive and intuitive anatomical information that helps with surgical planning,navigation,and outcome evaluation.AIM To discuss the application and advantages of 3D RVT in precise laparoscopic resection of EGJ carcinomas.METHODS Data were obtained from the electronic or paper-based medical records at The First Affiliated Hospital of Hebei North University from January 2020 to June 2022.A total of 120 patients diagnosed with EGJ carcinoma were included in the study.Of these,68 underwent laparoscopic resection after computed tomography(CT)-enhanced scanning and were categorized into the 2D group,whereas 52 underwent laparoscopic resection after CT-enhanced scanning and 3D RVT and were categorized into the 3D group.This study had two outcome measures:the deviation between tumor-related factors(such as maximum tumor diameter and infiltration length)in 3D RVT and clinical reality,and surgical outcome indicators(such as operative time,intraoperative blood loss,number of lymph node dissections,R0 resection rate,postoperative hospital stay,postoperative gas discharge time,drainage tube removal time,and related complications)between the 2D and 3D groups.RESULTS Among patients included in the 3D group,27 had a maximum tumor diameter of less than 3 cm,whereas 25 had a diameter of 3 cm or more.In actual surgical observations,24 had a diameter of less than 3 cm,whereas 28 had a diameter of 3 cm or more.The findings were consistent between the two methods(χ^(2)=0.346,P=0.556),with a kappa consistency coefficient of 0.808.With respect to infiltration length,in the 3D group,23 patients had a length of less than 5 cm,whereas 29 had a length of 5 cm or more.In actual surgical observations,20 cases had a length of less than 5 cm,whereas 32 had a length of 5 cm or more.The findings were consistent between the two methods(χ^(2)=0.357,P=0.550),with a kappa consistency coefficient of 0.486.Pearson correlation analysis showed that the maximum tumor diameter and infiltration length measured using 3D RVT were positively correlated with clinical observations during surgery(r=0.814 and 0.490,both P<0.05).The 3D group had a shorter operative time(157.02±8.38 vs 183.16±23.87),less intraoperative blood loss(83.65±14.22 vs 110.94±22.05),and higher number of lymph node dissections(28.98±2.82 vs 23.56±2.77)and R0 resection rate(80.77%vs 61.64%)than the 2D group.Furthermore,the 3D group had shorter hospital stay[8(8,9)vs 13(14,16)],time to gas passage[3(3,4)vs 4(5,5)],and drainage tube removal time[4(4,5)vs 6(6,7)]than the 2D group.The complication rate was lower in the 3D group(11.54%)than in the 2D group(26.47%)(χ^(2)=4.106,P<0.05).CONCLUSION Using 3D RVT,doctors can gain a more comprehensive and intuitive understanding of the anatomy and related lesions of EGJ carcinomas,thus enabling more accurate surgical planning. 展开更多
关键词 Gastroesophageal junction cancer ENDOSCOPY Tumor resection Three-dimensional reconstruction visualization Two-dimensional imaging computed tomography
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改性聚乳酸/生物玻璃复合纳米纤维的结构与性能 被引量:2
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作者 倪茂君 王静霞 +3 位作者 郭丹 陈屿恒 陈竹平 彭朝荣 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2019年第2期68-73,共6页
将辐照接枝改性聚乳酸(MPLLA)与纳米生物玻璃(NBG)复合,通过静电纺丝工艺制备MPLLA/NBG复合纳米纤维。利用红外光谱、扫描电镜、力学性能、表面接触角和体外矿化,研究聚乳酸接枝改性对复合纳米纤维结构及性能的影响。结果表明,辐射接枝... 将辐照接枝改性聚乳酸(MPLLA)与纳米生物玻璃(NBG)复合,通过静电纺丝工艺制备MPLLA/NBG复合纳米纤维。利用红外光谱、扫描电镜、力学性能、表面接触角和体外矿化,研究聚乳酸接枝改性对复合纳米纤维结构及性能的影响。结果表明,辐射接枝改性有利于提高聚乳酸与NBG之间的相容性,减小纳米粉体团聚,纤维直径减小,分布变窄;复合纳米纤维横向拉伸强度均大于5.5 MPa,纵向拉伸强度从3.9 MPa提高到5.5 MPa,横向、纵向拉伸强度差距随接枝率增大而减小;PLLA/NBG与10%MPLLA/NBG表面水接触角20 s内无明显差异,20%MPLLA/NBG表面水接触角20 s内从134.2°降低至78.6°;接枝改性提高了复合纳米纤维矿化度,20%MPLLA/NBG在24 h内快速矿化,14d矿化度较PLLA/NBG与10%MPLLA/NBG分别提高7.88倍和6.18倍。 展开更多
关键词 改性聚乳酸 生物玻璃 纳米纤维 拉伸强度 亲水性 体外矿化
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PBL教学法在生物医学工程专业C语言程序设计课程的初步实践 被引量:1
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作者 黄炳升 郑李韵 +3 位作者 赵振富 但果 汪天富 邓云 《中国教育技术装备》 2017年第22期124-126,共3页
探讨在生物医学工程专业C语言程序设计课程中运用基于问题学习(PBL)教学法的效果。学生分为实验组(22名)和对照组(42名),分别采用PBL教学法和传统授课模式。分析考试结果发现,实验组教学效果较好,在所有考题上的得分都优于对照组。可见... 探讨在生物医学工程专业C语言程序设计课程中运用基于问题学习(PBL)教学法的效果。学生分为实验组(22名)和对照组(42名),分别采用PBL教学法和传统授课模式。分析考试结果发现,实验组教学效果较好,在所有考题上的得分都优于对照组。可见PBL教学法有利于增强学生学习积极性,提高学生的动手能力,但仍需因材施教。 展开更多
关键词 PBL教学法 生物医学工程 教学改革 C语言程序设计
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Inhibiting endogenous tissue plasminogen activator enhanced neuronal apoptosis and axonal injury after traumatic brain injury 被引量:10
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作者 Jun-Jie Zhao Zun-Wei Liu +4 位作者 Bo Wang Ting-Qin Huang dan guo Yong-Lin Zhao Jin-Ning Song 《Neural Regeneration Research》 SCIE CAS CSCD 2020年第4期667-675,共9页
Tissue plasminogen activator is usually used for the treatment of acute ischemic stroke,but the role of endogenous tissue plasminogen activator in traumatic brain injury has been rarely reported.A rat model of traumat... Tissue plasminogen activator is usually used for the treatment of acute ischemic stroke,but the role of endogenous tissue plasminogen activator in traumatic brain injury has been rarely reported.A rat model of traumatic brain injury was established by weight-drop method.The tissue plasminogen activator inhibitor neuroserpin(5μL,0.25 mg/mL)was injected into the lateral ventricle.Neurological function was assessed by neurological severity score.Neuronal and axonal injuries were assessed by hematoxylin-eosin staining and Bielschowsky silver staining.Protein level of endogenous tissue plasminogen activator was analyzed by western blot assay.Apoptotic marker cleaved caspase-3,neuronal marker neurofilament light chain,astrocyte marker glial fibrillary acidic protein and microglial marker Iba-1 were analyzed by immunohistochemical staining.Apoptotic cell types were detected by immunofluorescence double labeling.Apoptotic cells in the damaged cortex were detected by terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP-biotin nick-end labeling staining.Degenerating neurons in the damaged cortex were detected by Fluoro-Jade B staining.Expression of tissue plasminogen activator was increased at 6 hours,and peaked at 3 days after traumatic brain injury.Neuronal apoptosis and axonal injury were detected after traumatic brain injury.Moreover,neuroserpin enhanced neuronal apoptosis,neuronal injury and axonal injury,and activated microglia and astrocytes.Neuroserpin further deteriorated neurobehavioral function in rats with traumatic brain injury.Our findings confirm that inhibition of endogenous tissue plasminogen activator aggravates neuronal apoptosis and axonal injury after traumatic brain injury,and activates microglia and astrocytes.This study was approved by the Biomedical Ethics Committee of Animal Experiments of Shaanxi Province of China in June 2015. 展开更多
关键词 apoptosis ASTROCYTES AXONAL INJURY inflammation microglia nerve REGENERATION neural REGENERATION neuronal INJURY neurons NEUROSERPIN tissue PLASMINOGEN activator traumatic brain INJURY
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血浆HOXA7基因甲基化在非小细胞肺癌诊断中的应用 被引量:6
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作者 郭丹 杨建伟 +1 位作者 杨亮 石科 《中国肿瘤临床》 CAS CSCD 北大核心 2019年第10期490-494,共5页
目的:检测非小细胞肺癌(non-small cell lungcancer,NSCLC)血浆中同源盒基因(homeobox,HOX)家族成员HOXA7基因启动子甲基化水平,并评估HOXA7甲基化与肿瘤标志物血清癌胚抗原(carcinoembryonic antigen,CEA)、糖类抗原(carbohydrate anti... 目的:检测非小细胞肺癌(non-small cell lungcancer,NSCLC)血浆中同源盒基因(homeobox,HOX)家族成员HOXA7基因启动子甲基化水平,并评估HOXA7甲基化与肿瘤标志物血清癌胚抗原(carcinoembryonic antigen,CEA)、糖类抗原(carbohydrate antigen199,CA199)和细胞角蛋白19片段抗原21-1(cytokeratin 19 fragment antigen 21-1,Cyfra21-1)水平辅助诊断NSCLC的价值。方法:选取河南省肿瘤医院2012年1月至2016年12月住院的经病理组织学确诊为NSCLC患者80例为试验组,50例健康人为对照组。采用定量甲基化特异性PCR(quantitativemethylation-specificPCR,q MSP)检测血浆HOXA7甲基化水平,电化学发光检测血浆CEA、CA199和Cyfra21-1水平。构建受试者工作特征曲线(ROC)分析各指标鉴别NSCLC的临床价值,并分析HOXA7甲基化与临床病例参数、肿瘤标志物之间的关系。结果:与健康对照组相比,NSCLC患者血浆中HOXA7基因甲基化水平异常增高(χ^2=36.972,P<0.0001),HOXA7甲基化诊断NSCLC的敏感度为68.8%(55/80),特异度为86.0%(43/50)。血浆HOXA7甲基化与性别、年龄、有无吸烟史和病理类型无关(均P>0.05),但与TNM分期有关(P<0.05),其中Ⅳ期患者血浆HOXA7甲基化水平最高。肿瘤标志物中Cyfra21-1诊断NSCLC的价值最高,敏感度为70.00%,特异度为90.00%。HOXA7甲基化联合三指标诊断NSCLC的效能最高(AUC=0.893,敏感度73.75%,特异度94%)。HOXA7甲基化与Cyfra21-1的相关系数最高(r=0.564,P<0.05)。结论:HOXA7基因甲基化水平对NSCLC的诊断有一定价值,与NSCLC的恶性程度相关,联合肿瘤标志物检测可以提高NSCLC的诊断效能。 展开更多
关键词 血浆 HOXA7基因甲基化 非小细胞肺癌 肿瘤标志物
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白皮杉醇对糖尿病视网膜病变模型大鼠的治疗效果及作用机制 被引量:4
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作者 郭丹 杜宁 《国际眼科杂志》 CAS 北大核心 2019年第12期2026-2030,共5页
目的:探究白皮杉醇对糖尿病视网膜病变模型大鼠的治疗效果及作用机制。方法:建立糖尿病视网膜病变模型,随机分为模型组、常规用药组、低剂量和高剂量白皮杉醇组各10只。模型组使用100mg/kg的生理盐水灌胃,常规用药组使用100mg/kg的依帕... 目的:探究白皮杉醇对糖尿病视网膜病变模型大鼠的治疗效果及作用机制。方法:建立糖尿病视网膜病变模型,随机分为模型组、常规用药组、低剂量和高剂量白皮杉醇组各10只。模型组使用100mg/kg的生理盐水灌胃,常规用药组使用100mg/kg的依帕司他灌胃,低剂量、高剂量白皮杉醇组分别使用100、200mg/kg白皮杉醇灌胃。使用光学显微镜观察五组大鼠视网膜组织,Western blot检测五组大鼠视网膜组织中Bax、Bcl-2蛋白的表达,酶联免疫吸附试验法检测五组大鼠视网膜组织VEGF、HIF-1α、ANGⅡ、Ang-1、Ang-2、Tie-2水平。结果:高剂量白皮杉醇组大鼠视网膜组织中Bax、Ang-1/Ang-2比值(1.76±0.05、3.16±0.09)高于低剂量白皮杉醇组(1.01±0.21、2.98±0.02)(P<0.05)。高剂量白皮杉醇组大鼠视网膜组织中Bcl-2、VEGF、HIF-1α、ANGⅡ、Ang-1、Ang-2、Tie-2水平(0.37±0.06ng/mL、121.89±5.45ng/mL、0.38±0.01pg/mL、7.58±0.10ng/mL、8.56±0.04μg/L、3.24±0.25μg/L、3.00±0.04μg/L)低于低剂量白皮杉醇组(0.96±0.21ng/mL、140.25±8.10ng/mL、0.42±0.02pg/mL、8.12±0.09ng/mL、9.10±0.46μg/L、4.12±0.23μg/L、3.46±0.15μg/L)(P<0.05)。结论:白皮杉醇通过作用于Ang/Tie受体信号通路,抑制氧化应激损伤、新生血管的生成,有效保护糖尿病视网膜病变大鼠的视网膜组织,且呈剂量依赖,为临床上治疗糖尿病视网膜病变的治疗提供了理论依据。 展开更多
关键词 白皮杉醇 糖尿病视网膜病变 血管生成素
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Analysis on the Effects of Morphological Traits of Lutraria sieboldii on Its Body Mass Trait 被引量:2
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作者 dan guo Jian CHEN +4 位作者 Ziqin ZHAI Tongtong REN Jijin WANG Lirong BAI Dahui YU 《Agricultural Biotechnology》 CAS 2021年第4期71-76,103,共7页
[Objectives]This study was conducted to explore the relationship between morphological traits and body mass trait of Lutraria sieboldii.[Methods]110 were randomly selected from 120 2^(nd)-instar L.sieboldii collected ... [Objectives]This study was conducted to explore the relationship between morphological traits and body mass trait of Lutraria sieboldii.[Methods]110 were randomly selected from 120 2^(nd)-instar L.sieboldii collected from the Tieshangang area of Beihai,Guangxi,and 132 were randomly selected from 150 shellfish at the instar of 0.6.Their morphological traits were measured:shell length(SL),shell height(SH),shell width(SW),anterior length(AL),posterior length(PL),nose length(NL)in closed shell state,and maximum open shell width(OS)between two shells in closed shell state,and the body mass trait BM was also measured.Statistical methods such as path analysis and multiple regression were used for data analysis,and the effects of these seven morphological traits on the body mass trait were studied,respectively.The correlation between the tested seven quantitative traits and one body mass trait was all positive,all reaching an extremely significant level(P<0.01).[Results]The body mass trait of the shellfish at the instar of 2 had the highest correlation coefficient with shell length(0.922),that is,shell length had the greatest direct impact on the body mass trait;the path coefficient was 0.700;and the final multiple regression equation established was BM=-124.882+1.189 SL+1.551 SH+1.035 SW+0.119 NL,and the total determination coefficient(R^(2))on body mass was 0.849.The body mass trait of the shellfish at the instar of 0.6 had the highest correlation coefficient with shell length(0.859),that is,shell length had the greatest direct impact on the body mass trait;the path coefficient was 0.494;and the final multiple regression equation established was BM=-1.917+0.111 SL+0.021 NL+0.078 SW+0.032 OS,and the total determination coefficient(R~2)on body mass was 0.828.The multivariate regression variance analysis showed that the regression between the morphological traits and body mass trait of the L.sieboldii at the instars of 2 and 0.6 reached an extremely significant level(P<0.01).[Conclusions]This study provides a scientific basis for the selection of broodstock in the selection and breeding of L.sieboldii. 展开更多
关键词 Lutraria sieboldi Morphological traits Correlation analysis Multiple regression Path analysis
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Table-like shape magnetocaloric effect and large refrigerant capacity in dual-phase HoNi/HoNi2 composite 被引量:1
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作者 郭丹 张义坤 +2 位作者 王雅鸣 王江 任忠鸣 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第10期484-487,共4页
Nowadays,magnetic cooling(MC) technology by using the magnetocaloric effect(MCE) has attracted extensive research interest for its promising practical applications.A constant large/giant MCE covers wide refrigeration ... Nowadays,magnetic cooling(MC) technology by using the magnetocaloric effect(MCE) has attracted extensive research interest for its promising practical applications.A constant large/giant MCE covers wide refrigeration temperatures(denote as table-like shape) is beneficial for obtaining high efficiency performance for MC.In this paper,the HoNi/HoNi2 composite was successfully synthesized by arc-melting method and proved to be composed of HoNi and HoNi2 crystalline phases with weight ratios of 52.4 wt.% and 47.6 wt.%,respectively.The maximum magnetic entropy change(-ΔSMmax)is 18.23 J/(kg·K),and the refrigerant capacity values RC1,RC2,and RC3 are 867.9 J/kg,676.4 J/kg,and 467.8 J/kg with ΔH=0-70 kOe,respectively.The table-like shape MCE and large refrigerant capacity values make the composite attractive for cryogenic MC using the Ericsson cycle. 展开更多
关键词 HoNi-HoNi2 composite magnetic refrigeration table-like magnetocaloric effect
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热喷涂铜铝聚苯酯封严涂层制备和性能研究 被引量:8
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作者 刘通 刘建明 +2 位作者 郭丹 黄凌峰 章德铭 《热喷涂技术》 2020年第1期57-61,33,共6页
本文以铜铝合金粉和聚苯酯为原材料,添加粘结剂,采用机械团聚复合工艺制备铜铝聚苯酯复合粉末;采用大气等离子喷涂工艺制备的铜铝聚苯酯封严涂层组织均匀,聚苯酯和孔隙占比45.3%,涂层硬度为56.3 HR15Y、结合强度≥6.9MPa、650℃下抗热... 本文以铜铝合金粉和聚苯酯为原材料,添加粘结剂,采用机械团聚复合工艺制备铜铝聚苯酯复合粉末;采用大气等离子喷涂工艺制备的铜铝聚苯酯封严涂层组织均匀,聚苯酯和孔隙占比45.3%,涂层硬度为56.3 HR15Y、结合强度≥6.9MPa、650℃下抗热震性能良好,涂层在96小时室温中性盐雾试验外观评级达到4级,可满足航空发动机对气路间隙控制封严涂层的要求。 展开更多
关键词 铜铝聚苯酯 封严涂层 等离子喷涂 力学性能 耐腐蚀性
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First-Principles Study of Intrinsic Point Defects of Monolayer GeS
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作者 邱晨 曹茹月 +7 位作者 张才鑫 张陈 郭丹 沈涛 刘竹友 胡玉莹 王飞 邓惠雄 《Chinese Physics Letters》 SCIE CAS CSCD 2021年第2期57-61,共5页
The properties of six kinds of intrinsic point defects in monolayer GeS are systematically investigated using the“transfer to real state”model,based on density functional theory.We find that Ge vacancy is the domina... The properties of six kinds of intrinsic point defects in monolayer GeS are systematically investigated using the“transfer to real state”model,based on density functional theory.We find that Ge vacancy is the dominant intrinsic acceptor defect,due to its shallow acceptor transition energy level and lowest formation energy,which is primarily responsible for the intrinsic p-type conductivity of monolayer GeS,and effectively explains the native p-type conductivity of GeS observed in experiment.The shallow acceptor transition level derives from the local structural distortion induced by Coulomb repulsion between the charged vacancy center and its surrounding anions.Furthermore,with respect to growth conditions,Ge vacancies will be compensated by fewer n-type intrinsic defects under Ge-poor growth conditions.Our results have established the physical origin of the intrinsic p-type conductivity in monolayer GeS,as well as expanding the understanding of defect properties in lowdimensional semiconductor materials. 展开更多
关键词 VACANCY CONDUCTIVITY DEFECT
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利用排列小波熵评价脑电信号中的爆发抑制水平
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作者 袁思念 但果 +5 位作者 叶继伦 张旭 牛航舵 马胜才 李若薇 朱子孚 《中国医学物理学杂志》 CSCD 2022年第8期1010-1014,共5页
为了评价脑电信号的爆发抑制水平,本文从非线性动力学的角度出发,通过计算脑电信号的排列熵,再计算排列熵的小波熵,得到一种新的参数排列小波熵(PEWE)于量化脑电信号的爆发抑制水平。结果表明,在4例数据的测试中,PEWE与双谱指数模块输... 为了评价脑电信号的爆发抑制水平,本文从非线性动力学的角度出发,通过计算脑电信号的排列熵,再计算排列熵的小波熵,得到一种新的参数排列小波熵(PEWE)于量化脑电信号的爆发抑制水平。结果表明,在4例数据的测试中,PEWE与双谱指数模块输出的爆发抑制比指数的相关系数达0.9425,因此,PEWE可以作为一种新参数来量化EEG信号的爆发抑制水平,为评价EEG信号的爆发抑制水平提供了新思路。 展开更多
关键词 脑电信号 爆发抑制水平 排列熵 小波熵
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Embodied Cognition From the Perspective of Vygotsky’s Socio-cultural Theory
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作者 Xuejiao Zhang Huili Wang dan guo 《Journal of Philosophy Study》 2018年第8期362-367,共6页
关键词 社会文化 文化环境 相互作用 认知科学 符号系统 身体 两重性 方法论
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The Significance of Image Schema in Embodied Cognition
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作者 dan guo Huili Wang 《Journal of Philosophy Study》 2018年第8期355-361,共7页
关键词 图象 相互作用 心理学 语言学 逻辑性 身体 说服力 性质
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The Philosophical Basis of Social Turning of Embodied Cognition From the Perspective of Symbolic Interactionism
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作者 Xin Chang Huili Wang +1 位作者 dan guo Zhongliang Cui 《Journal of Philosophy Study》 2018年第7期309-314,共6页
Since the 1990s,embodied cognition has become the research trend of cognitive science.Due to excessive attention to embodiment and the physical environment,embodied cognition does not pay more attention to the social ... Since the 1990s,embodied cognition has become the research trend of cognitive science.Due to excessive attention to embodiment and the physical environment,embodied cognition does not pay more attention to the social characteristics of cognition,especially the role of others and symbolic activities,making cognitive science research unable to get rid of solipsism.So,it is difficult for the embodied cognition to explain the uniformity and multiplicity of cognition,and the problem of“other”mind.To solve these problems,the paper expounds the relations between symbolic interactionism and embodied cognition and the necessity of social turning in embodied cognition.Through analyzing the thoughts of George H.Mead about cognition and the influence of his symbolic interactionism on embodied cognition,as well as discussing Mark Johnson’s view on social interactional aspects of embodied cognition,we emphasize that the social and symbolic interactions are indispensable factors of embodied cognition.The paper argues that higher-order cognition comes out of symbolic interactions;cognition generates from posture dialogue interaction and manifests itself through attitude;intersubjectivity is closely associated with symbolic interactionism.Therefore,studying the relations between symbolic interactionism and embodied cognition helps overcome the solipsism or individualism of embodied cognition,and accordingly contributes to the social turning of embodied cognition. 展开更多
关键词 SYMBOLIC INTERACTION SOCIAL TURNING EMBODIED COGNITION
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Comparative analysis of frictional behavior and mechanism of molybdenum ditelluride with different structures
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作者 Lina ZHANG Xinfeng TAN +2 位作者 Jianguo JIAO dan guo Jianbin LUO 《Friction》 SCIE EI CAS CSCD 2024年第1期110-119,共10页
Two-dimensional(2D)transition metal dichalcogenides(TMDCs)have layered structures with excellent tribological properties.Since the energy difference between hexagonal-molybdenum ditelluride(2H-MoTe_(2))and distorted o... Two-dimensional(2D)transition metal dichalcogenides(TMDCs)have layered structures with excellent tribological properties.Since the energy difference between hexagonal-molybdenum ditelluride(2H-MoTe_(2))and distorted octahedral-molybdenum ditelluride(1T′-MoTe_(2))is very small among the transition metal dichalcogenides(TMDCs),MoTe_(2) becomes one of the most promising candidates for phase engineering.In our experiment,we found that the friction force and friction coefficient(COF)of 2H-MoTe_(2) were an order of magnitude smaller than those of 1T′-MoTe_(2) by the atomic force microscope(AFM)experiments.The friction difference between 1T′-MoTe_(2) and 2H-MoTe_(2) was further verified in molecular dynamics(MD)simulations.The density functional theory(DFT)calculations suggest that the friction contrast is related to the difference in sliding energy barrier of the potential energy surface(PES)for a tip sliding across the surface.The PES obtained from the DFT calculation indicates that the maximum energy barrier and the minimum energy path(MEP)energy barrier of 2H-MoTe_(2) are both smaller than those of 1T′-MoTe_(2),which means that less energy needs to be dissipated during the sliding process.The difference in energy barrier of the PES could be ascribed to its larger interlayer spacing and weaker Mo–Te interatomic interactions within the layers of 2H-MoTe_(2) than those of 1T′-MoTe_(2).The obvious friction difference between 1T′-MoTe_(2) and 2H-MoTe_(2) not only provides a new non-destructive means to detect the phase transition by the AFM,but also provides a possibility to tune friction by controlling the phase transition,which has the potential to be applied in extreme environments such as space lubrication. 展开更多
关键词 FRICTION two-dimensional(2D)materials distorted octahedral-molybdenum ditelluride(1T′-MoTe_(2)) hexagonal-molybdenum ditelluride(2H-MoTe_(2)) phase transition
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医用氧气浓度监测与校准方法
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作者 叶继伦 李明月 +2 位作者 王磊 但果 宋学东 《中国医疗器械信息》 2023年第11期37-40,共4页
医用氧气是医院麻醉、重症监护、急诊等科室的常用气体,对医用氧气浓度进行准确的实时监测是保证临床用氧安全的必要手段。目前,针对不同的预期应用,常用的氧气监测方法有电化学法、顺磁法以及利用超声技术实现氧气浓度监测的方法。重... 医用氧气是医院麻醉、重症监护、急诊等科室的常用气体,对医用氧气浓度进行准确的实时监测是保证临床用氧安全的必要手段。目前,针对不同的预期应用,常用的氧气监测方法有电化学法、顺磁法以及利用超声技术实现氧气浓度监测的方法。重点介绍上述几种方法的工作原理,并针对临床氧气监测需要进行定期校零与校准的实际情况,提出一种医用氧气浓度的校准方法,对深圳惟拓力医疗电子公司研发的顺磁氧监测模块按该方法进行测试,结果表明其具有良好的校零与校准效果。该方法学可为相关产品校准提供一定参考。 展开更多
关键词 氧气监测 校准 校零
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基于嫦娥五号月球样品的月壤残余内摩擦角预测 被引量:2
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作者 聂家岩 崔一飞 +13 位作者 Kostas Senetakis 郭丹 王瑜 王国栋 冯鹏 贺怀宇 张徐航 张小平 李存惠 郑虎 胡伟 牛富俊 刘权兴 李安原 《Science Bulletin》 SCIE EI CAS CSCD 2023年第7期730-739,共10页
随着人类探月工程的快速发展,月球基地建设以及月表资源开发利用有望更快实现,合理预测月壤工程力学性质对于未来深层次探月工程意义重大,我国嫦娥五号返回月球样品为研究月壤工程力学特性提供了直接的实测材料。然而,月球样品极其珍贵... 随着人类探月工程的快速发展,月球基地建设以及月表资源开发利用有望更快实现,合理预测月壤工程力学性质对于未来深层次探月工程意义重大,我国嫦娥五号返回月球样品为研究月壤工程力学特性提供了直接的实测材料。然而,月球样品极其珍贵,难以满足传统土工试验测试.为了应对这一科学挑战,本研究从无损分析月球样品颗粒属性入手,使用高精度X-射线μCT扫描、三维白光干涉、原子力显微镜等无损测试手段,分析了不同类型月壤颗粒的三维多尺度形态、弹性力学和摩擦属性等指标.在此基础上,基于颗粒材料宏微观物理力学理论和数值模型尝试预测了嫦娥五号采样处月壤残余内摩擦角。本研究为基于月球样品信息跨尺度分析月壤工程力学性质提供了可行思路。 展开更多
关键词 Chang’e-5 lunar samples Geometry MECHANICS TRIBOLOGY Residual friction angle Cross-scale prediction
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Printable microlaser arrays with programmable modes for information encryption 被引量:1
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作者 Jun Ruan dan guo +3 位作者 Kun Ge Zhiyang Xu Fangyuan Liu Tianrui Zhai 《Nano Research》 SCIE EI CSCD 2023年第7期10100-10107,共8页
Lasing emissions with multiple and tunable modes are promising in coding field as a novel cryptographic primitive.With the advantages of simple fabrication,full-color and high-quality-factor whispering gallery mode la... Lasing emissions with multiple and tunable modes are promising in coding field as a novel cryptographic primitive.With the advantages of simple fabrication,full-color and high-quality-factor whispering gallery mode lasing inside a circular cross-section,polymer microfibers are attractive for photonic devices.However,polymer lasing microfibers for information encryption have never been reported.Herein,we propose a design of printable lasing microfiber encryption chip by in-situ tuning the effective refractive index of the microresonator arrays via a facile approach.Through inkjet printing high-refractive-index nanoparticles on the designated position of lasing microfiber arrays,the effective refractive index of the microcavities is regulated,and the ratio of wavenumber spacing between transverse electric and transverse magnetic mode to the free spectral range can be modulated,particularly with neglectable influence by the size factor.Thus,the programmable region selective encoding process can be conducted simply by a printing program within several minutes.Besides,the encoded microfiber arrays are encapsulated into polydimethylsiloxane to reduce the scattering loss and environmental interference,and a printable encryption chip is realized.This work is expected to provide a platform for the printable encrypted devices. 展开更多
关键词 polymer microfiber whispering gallery mode microcavity laser POLARIZATION mode spacing optical encryption
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重稀土HRENiGa_(2)(HRE=Dy,Ho或Er)化合物的优异低温磁热性能
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作者 郭丹 Luis M.Moreno-Ramírez +2 位作者 Jia-Yan Law 张义坤 Victorino Franco 《Science China Materials》 SCIE EI CAS CSCD 2023年第1期249-256,共8页
RENiX_(2)化合物(其中RE为稀土元素,X为p区元素)在低温磁制冷应用中受到高度关注.它们根据元素的不同可以结晶成CeNiSi_(2)型、NdNiGa_(2)型或MgCuAl_(2)型晶体结构,并表现出不同类型的磁有序性从而影响其磁性.MgCuAl_(2)型铝化物由于... RENiX_(2)化合物(其中RE为稀土元素,X为p区元素)在低温磁制冷应用中受到高度关注.它们根据元素的不同可以结晶成CeNiSi_(2)型、NdNiGa_(2)型或MgCuAl_(2)型晶体结构,并表现出不同类型的磁有序性从而影响其磁性.MgCuAl_(2)型铝化物由于具有有利的铁磁基态从而表现出比CeNiSi_(2)型硅化物和NdNiGa_(2)型镓化物更大的磁热性能.此外,RENiGa_(2)镓化物根据RE元素的不同可以结晶成NdNiGa_(2)或MgCu Al_(2)型结构.本文中,我们选择重稀土(HRE)元素来探索HRENiGa_(2)(HRE=Dy,Ho或Er)镓化物的微观结构、磁有序和磁热性能.三种化合物均以MgCuAl_(2)型晶体结构结晶,并且随着温度的升高经历了从铁磁到顺磁的二级磁相转变.DyNiGa_(2),HoNiGa_(2)和ErNiGa_(2)化合物的最大等温磁熵变(|ΔSisomax|)值分别为6.2,10.4和11.4 J kg^(-1)K^(-1)(0-5T),这与许多最近报道的低温磁制冷材料性能相当.特别地,HoNiGa_(2)和ErNiGa_(2)化合物(包括它们的复合材料)在氢气液化的温度范围内表现出优异的磁热性能. 展开更多
关键词 重稀土 磁热性能 晶体结构 磁制冷材料 稀土元素 磁有序 等温磁熵变 硅化物
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Interlayer friction behavior of molybdenum ditelluride with different structures
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作者 Lina Zhang Xinfeng Tan +2 位作者 Jianguo Jiao dan guo Jianbin Luo 《Nano Research》 SCIE EI CSCD 2023年第8期11375-11382,共8页
The interlayer friction behavior of two-dimensional transition metal dichalcogenides(TMDCs)as crucial solid lubricants has attracted extensive attention in the field of tribology.In this study,the interlayer friction ... The interlayer friction behavior of two-dimensional transition metal dichalcogenides(TMDCs)as crucial solid lubricants has attracted extensive attention in the field of tribology.In this study,the interlayer friction is measured by laterally pushing the MoTe_(2)powder on the MoTe_(2)substrate with the atomic force microscope(AFM)tip,and density functional theory(DFT)simulations are used to rationalize the experimental results.The experimental results indicate that the friction coefficient of the 1T'-MoTe_(2)/1T'-MoTe_(2)interface is 2.025×10^(−4),which is lower than that of the 2H-MoTe_(2)/2H-MoTe_(2)interface(3.086×10^(−4)),while the friction coefficient of the 1T'-MoTe_(2)/2H-MoTe_(2)interface is the lowest at 6.875×10^(−5).The lower interfacial friction of 1T'-MoTe_(2)/1T'-MoTe_(2)compared to 2H-MoTe_(2)/2H-MoTe_(2)interface can be explained by considering the relative magnitudes of the ideal average shear strengths and maximum shear strengths based on the interlayer potential energy.Additionally,the smallest interlayer friction observed at the 1T'-MoTe_(2)/2H-MoTe_(2)heterojunction is attributed to the weak interlayer electrostatic interaction and reduction in potential energy corrugation caused by the incommensurate contact.This work suggests that MoTe_(2)has comparable interlayer friction properties to MoS_(2)and is expected to reduce interlayer friction in the future by inducing the 2H-1T'phase transition. 展开更多
关键词 two-dimensinal materials MoTe_(2) interlayer friction interlayer shear strength
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