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Biaxial stretching of polytetrafluoroethylene in industrial scale to fabricate medical ePTFE membrane with node-fibril microstructure

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Regenerative Biomaterials 2023年第1期10卷 1161-1177页

作者： Gang Wang Yusheng feng Caiyun Gao Xu Zhang Qunsong Wang Jie Zhang Hongjie Zhang YongqiangWu Xin Li Lin Wang Ye Fu Xiaoye Yu Deyuan Zhang Jianxiong Liu jiandong Ding State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai 200438China R&D Center Lifetech Scientific(Shenzhen)Co.Ltd.Shenzhen 518057China R&D Center Lifevalve Medical Scientific Co.Ltd.Shenzhen 518057China

Expanded polytetrafluoroethylene(ePTFE)is promising in biomedical fields such as covered stents and plastic surgery owing to its excellent biocompatibility and mechanical ***,ePTFE material prepared by the traditional biaxial stretching process is with thicker middle and thinner sides due to the bowing effect,which poses a major problem in industrial-scale *** solve this problem,we design an olive-shaped winding roller to provide the middle part of the ePTFE tape with a greater longitudinal stretching amplitude than the two sides,so as to make up for the excessive longitudinal retraction tendency of the middle part when it is transversely *** as-fabricated ePTFE membrane has,as designed,uniform thickness and node-fibril *** addition,we examine the effects of mass ratio of lubricant to PTFE powder,biaxial stretching ratio and sintering temperature on the performance of the resultant ePTFE ***,the relation between the internal microstructure of the ePTFE membrane and its mechanical properties is *** stable mechanical properties,the sintered ePTFE membrane exhibits satisfactory biological *** make a series of biological assessments including in vitro hemolysis,coagulation,bacterial reverse mutation and in vivo thrombosis,intracutaneous reactivity test,pyrogen test and subchronic systemic toxicity test;all of the results meet the relevant international *** muscle implantation of the sintered ePTFE membrane into rabbits indicates acceptable inflammatory reactions of our sintered ePTFE membrane fabricated on industrial *** a medical-grade raw material with the unique physical form and condensed-state microstructure is expected to afford an inert biomaterial potentially for stent-graft membrane.

关键词： biomedical polymer medical-grade raw material expanded polytetrafluoroethylene olive roller polymer processing biaxial stretching

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Electrolytes enriched by potassium perfluorinated sulfonates for lithium metal batteries

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Science Bulletin 2021年第7期66卷 685-693,M0004页

作者： Shihan Qi Huaping Wang Jian He jiandong Liu Chunyu Cui Mingguang Wu Fang Li Yuezhan feng Jianmin Ma School of Physics and Electronics Hunan UniversityChangsha 410082China Key Laboratory of Materials Processing and Mold(Zhengzhou University) Ministry of EducationZhengzhou UniversityZhengzhou 450002China

Lithium(Li) metal is widely considered as a promising anode for next-generation lithium metal batteries(LMBs) due to its high theoretical capacity and lowest electrochemical potential. However, the uncontrollable formation of Li dendrites has prevented its practical application. Herein, we propose a kind of multifunctional electrolyte additives(potassium perfluorinated sulfonates) from the multi-factor principle for electrolyte additive molecular design(EDMD) view to suppress the Li dendrite growth. The effects of these additives are revealed through experimental results, molecular dynamics simulations and firstprinciples calculations. Firstly, K^(+)can form an electrostatic shield on the surface of Li anode to prevent the growth of Li dendrites. Secondly, potassium perfluorinated sulfonates can improve the activity of electrolytes as co-conductive salts, and lower the electro-potential of Li nucleation. Thirdly, perfluorinated sulfonate anions not only can change the Li^(+)solvation sheath structure to decrease the desolvation energy barrier and increase the ion migration rate, but also can be partly decomposed to form the superior solid electrolyte interphase(SEI). Benefited from the synergistic effects, an outstanding cycle life over250 h at 1 m A cm^(-2) is achieved in symmetric Li||Li cells. In particular, potassium perfluorinated sulfonate additives(e.g., potassium perfluorohexyl sulfonate, denoted as K+PFHS) can also contribute to the formation of high-quality cathode electrolyte interphase(CEI). As a result, Li||LiNi_(0.6)Mn_(0.2)Co_(0.2)O_(2) full cells exhibit significantly enhanced cycling stability. This multi-factor principle for EDMD offers a unique insight on understanding the electrochemical behavior of ion-type electrolyte additives on both the Li metal anode and high-voltage cathode.

关键词： Electrolyte Additives Lithium metal batteries Lithium anode protection Potassium perfluorinated sulfonates

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High temperature performance of coaxial h-BN/CNT wires above 1,000 ℃:Thermionic electron emission and thermally activated conductivity

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Nano Research 2019年第8期12卷 1855-1861页

作者： Xinhe Yang Peng Liu Duanliang Zhou feng Gao Xinhe Wang Shiwei Lv Zi Yuan Xiang Jin Wei Zhao Haoming Wei Lina Zhang jiandong Gao Qunqing Li Shoushan Fan Kaili Jiang State Key Laboratory of Low-Dimensional Quantum Physics Department of Physics and Tsinghua-Foxconn Nanotechnology Research CenterTsinghua UniversityBeijing 100084China Yantai HeFuXiang Ceramics Co. LtdYantai 265205China Fert Beijing Research Institute School of Microelectronics and Beijing Advanced Innovation Center for Big Data and Brain Computing (BDBC)Beihang UniversityBeijing 100191China

The development of wires and cables that can tolerate extremely high temperatures will be very important for probing extreme environments, such as in solar exploration, fire disasters, high-temperature materials processing, aeronautics and astronautics. In this paper, a lightweight high-temperature coaxial h-boron nitride (BN)/carbon nanotube (CNT) wire is synthesized by the chemical vapor deposition (CVD) epitaxial growth of h-BN on CNT yarn. The epitaxially grown h-BN acts as both an insulating material and a jacket that protects against oxidation. It has been shown that the thermionic electron emission (1,200 K) and thermally activated conductivity (1,000 K) are two principal mechanisms for insulation failure of h-BN at high temperatures. The thermionic emission of h-BN can provide the work function of h-BN, which ranges from 4.22 to 4.61 eV in the temperature range of 1,306-1,787 K. The change in the resistivity of h-BN with temperature follows the ohmic conduction model of an insulator, and it can provide the “electron activation energy”(the energy from the Fermi level to the conduction band of h-BN), which ranges from 2.79 to 3.08 eV, corresponding to a band gap for h-BN ranging from 5.6 to 6.2 eV. However, since the leakage current is very small, both phenomena have no obvious influence on the signal transmission at the working temperature. This lightweight coaxial h-BN/CNT wire can tolerate 1,200 ℃ in air and can transmit electrical signals as normal. It is hoped that this lightweight high-temperature wire will open up new possibilities for a wide range of applications in extreme high-temperature conditions.

关键词： high temperature wire carbon nanotube (CNT) h-boron nitride (h-BN) work function bandgap

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线粒体功能障碍调控慢性肾脏病机制及中药治疗的研究进展

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中华中医药学刊 2024年第3期42卷 198-202,I0029,I0030页

作者：张栩铭周嘉宝杨枫吴志远高建东上海中医药大学附属曙光医院上海201203 上海中医药大学中医肾病研究所上海201203 上海市中医临床重点实验室(20DZ2272200) 上海201203 上海中医药大学肝肾疾病病证教育部重点实验室上海201203

慢性肾脏病(chronic kidney disease, CKD)属于肾内科常见疾病,是由多因素共同参与而导致的肾脏损伤或肾功能下降。近年来CKD,尤其是终末期CKD患者发病率、住院率均明显升高,严重威胁着患者生命健康安全。而线粒体在细胞能量代谢与生成... 详细信息

慢性肾脏病(chronic kidney disease, CKD)属于肾内科常见疾病,是由多因素共同参与而导致的肾脏损伤或肾功能下降。近年来CKD,尤其是终末期CKD患者发病率、住院率均明显升高,严重威胁着患者生命健康安全。而线粒体在细胞能量代谢与生成中发挥着重要的作用,其功能障碍可导致患者肾脏能量供应不足、发生氧化应激损伤等,现已成为世界性公共卫生问题之一。鉴于此,基于相关研究,阐述线粒体的结构及功能,从线粒体氧化应激、线粒体自噬、线粒体过度分裂与融合缺陷、线粒体生物合成功能障碍几个方面,分析线粒体功能障碍在CKD发病机制及治疗中的作用,概述中药及其提取物通过保护线粒体功能,旨在为临床治疗CKD提供新思路。

关键词：线粒体功能障碍慢性肾脏病发病机制中医药靶向治疗

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Mechanism and genesis of Sanmen Bay as a sink of Holocene Yangtze River sediment,Zhejiang Province,China

Mechanism and genesis of Sanmen Bay as a sink of Holocene Ya...

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第十七届全国古地理学及沉积学学术会议

作者： jiandong Qiu Shenghui Jiang Jing feng Qingdao Institute of Marine Geology China Geological Survey

The Holocene mud deposits that extend from the Yangtze River mouth to the Taiwan Strait along the Zhejiang–Fujian coast,East China Sea（ECS）,have attracted onsiderable research attention. However,there is a lack of consensus regarding the redistribution flux of Yangtze River sediment after it enters the sea. There are many bays along the Zhejiang and Fujian coasts,but their role in the source–sink process of Yangtze River sediment is not well-documented owing to limited data. In this study,data from shallow seismic profiles,core samples,and surface sediment samples were analysed to assess the role of Sanmen Bay,the second largest bay in Zhejiang Province,in the source–sink process of Yangtze River sediments. The results showed that Sanmen Bay is an important sink for Yangtze River sediments. The characteristics of the clay minerals indicate that the fine-grained sediments in Sanmen Bay are mainly derived from Yangtze River sediments. The thickness of Holocene deposits in Sanmen Bay ranges from 8.2 to 32.0 m,with an average of 23.4 m and a total sediment volume of 5.06 × 10～4 Mt,accounting for 1% of Yangtze River sediment in this time period. The Bayesian age-depth model based on borehole accelerator mass spectrometry（AMS） C dating shows that a high sedimentation rate occurred in the early and late Holocene but decreased significantly in the mid-Holocene,which is similar to that of the inner shelf of the East China Sea（ECS）. The variation in the Holocene sedimentation rate in Sanmen Bay is related to the southward transport process and mechanism of Yangtze River sediments. The results of this study provide a basis for understanding the source–sink process of sediment in large rivers.

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关中地区地源热泵系统应用及节能分析

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绿色科技 2018年第16期20卷 175-177页

作者：李晓琳茹秋瑾冯建栋田佳杨凌职业技术学院水利工程分院陕西杨凌712100

指出了石化能源的消耗引起了巨大的环境压力。针对陕西关中地区冬冷夏热的气候特点,结合地源热泵系统的应用实例,将其与燃煤集中供热+分体空调制冷的系统进行了对比,分析了地源热泵系统的节能效益及环境影响,为陕西关中地区的能源结构... 详细信息

指出了石化能源的消耗引起了巨大的环境压力。针对陕西关中地区冬冷夏热的气候特点,结合地源热泵系统的应用实例,将其与燃煤集中供热+分体空调制冷的系统进行了对比,分析了地源热泵系统的节能效益及环境影响,为陕西关中地区的能源结构改善提供思路。

关键词：地源热泵节能分析环境影响

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光谱特征和纹理特征融合的红茶萎凋含水率检测方法

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茶叶通讯 2024年第3期51卷 376-382页

作者：沈跃铖阮贤萍郎春晓冯科达沈帅郑航张诚荣蒋建东俞国红浙江工业大学机械工程学院浙江杭州310014 绍兴市上虞区农业机械化技术推广中心浙江绍兴312300 浙江省农业科学院浙江杭州310021 浙江红茗茶机成套技术有限公司浙江绍兴312300

为实现对红茶萎凋含水率的定量检测,研究提出了一种基于谱图特征融合的红茶萎凋含水率检测方法。通过采集不同萎凋时刻的高光谱图像,利用灰度共生矩阵法提取图像的7个纹理特征并与提取到的光谱特征相融合;通过采用PLSR、RF和GBDTR建立... 详细信息

为实现对红茶萎凋含水率的定量检测,研究提出了一种基于谱图特征融合的红茶萎凋含水率检测方法。通过采集不同萎凋时刻的高光谱图像,利用灰度共生矩阵法提取图像的7个纹理特征并与提取到的光谱特征相融合;通过采用PLSR、RF和GBDTR建立含水率预测模型,分析光谱特征、纹理特征以及“光谱特征+纹理特征”对含水率预测的准确性,实现红茶萎凋含水率快速无损检测。结果表明融合后的特征效果均得到较大提升,相比于其他两种模型,PLSR表现良好,在测试集上特征融合后的决定系数R2达0.7932,相较于光谱特征和纹理特征分别提升0.047和0.039。该研究对红茶加工设备的智能化具有重要意义,同时所提出的基于谱图特征融合的模型为红茶萎凋过程的智能检测提供了新思路。

关键词：红茶萎凋光谱特征纹理特征含水率检测方法预测模型

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FAST FEATURE RANKING AND ITS APPLICATION TO FACE RECOGNITION

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Transactions of Nanjing University of Aeronautics and Astronautics 2013年第4期30卷 389-396页

作者：潘锋王建东宋广为牛奔顾其威 College of Management Shenzhen University College of Computer Science and Technology Nanjing University of Aeronautics and Astronautics

A fast feature ranking algorithm for classification in the presence of high dimensionahty and small sample size is proposed. The basic idea is that the important features force the data points of the same class to maintain their intrinsic neighbor relations, whereas neighboring points of different classes are no longer to stick to one an- other. Applying this assumption, an optimization problem weighting each feature is derived. The algorithm does not involve the dense matrix eigen-decomposition which can be computationally expensive in time. Extensive exper- iments are conducted to validate the significance of selected features using the Yale, Extended YaleB and PIE data- sets. The thorough evaluation shows that, using one-nearest neighbor classifier, the recognition rates using 100-- 500 leading features selected by the algorithm distinctively outperform those with features selected by the baseline feature selection algorithms, while using support vector machine features selected by the algorithm show less prominent improvement. Moreover, the experiments demonstrate that the proposed algorithm is particularly effi- cient for multi-class face recognition problem.

关键词： feature selection feature ranking manifold learning Laplacian matrix

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国有林场森林经营类型制定研究——以长岛县国有长岛林场为例

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热带林业 2024年第1期52卷 8-11页

作者：李建东冯金鑫谢茂文孙妮妮韩雪涛左效桂刘成杰威海市文登区昆嵛山国家级自然保护区综合服务中心山东威海264400 山东长岛国家级自然保护区管理中心山东烟台264000 山东省烟台护士学校山东烟台264000 烟台市森林资源监测保护服务中心山东烟台264000

该文以2019年度二类调查数据为基础,对长岛县国有长岛林场森林经营类型进行了研究。根据长岛森林所处的位置、生态条件、主导功能与分类经营的要求,进行森林经营类型组划分,并就两类森林经营类型组的功能定位、发展布局和经营技术措施... 详细信息

该文以2019年度二类调查数据为基础,对长岛县国有长岛林场森林经营类型进行了研究。根据长岛森林所处的位置、生态条件、主导功能与分类经营的要求,进行森林经营类型组划分,并就两类森林经营类型组的功能定位、发展布局和经营技术措施进行了阐述。探索适宜海岛的森林经营方案,为海岛型国有林场改革后的森林经营提供示范。

关键词：森林国有林场森林经营

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矩形渡槽水力计算的Excel求解

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山西建筑 2015年第23期41卷 216-217页

作者：韩红亮刘守宇王雪梅冯建栋杨凌职业技术学院水利工程学院陕西杨凌712100 重庆市建筑科学研究院重庆400020

针对矩形渡槽水力计算涉及到槽身底坡和底宽的拟定、正常水深计算等问题,分析过程复杂,计算量较大的现象,将常用的Excel软件应用于矩形渡槽的水力计算,通过编制试算、IF()语句等计算程序,实现了矩形渡槽水力计算的快速求解,减小了计算量... 详细信息

针对矩形渡槽水力计算涉及到槽身底坡和底宽的拟定、正常水深计算等问题,分析过程复杂,计算量较大的现象,将常用的Excel软件应用于矩形渡槽的水力计算,通过编制试算、IF()语句等计算程序,实现了矩形渡槽水力计算的快速求解,减小了计算量,提高了设计效率。

关键词：矩形渡槽水力计算 Excel

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