检索结果-南通市图书馆

Enhanced thermoelectric performance of spark plasma sintered p-type Ca_(3-x)Y_(x)Co_(4)O_(9+δ)systems

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2020年第20期52卷 212-222页

作者： J.S.cha D.H.Kim H.Y.Hong K.Park Faculty of Nanotechnology and Advanced Materials Engineering Sejong UniversitySeoul05006Republic of Korea

Highly textured dense Ca3-xYxCo4 O9+δ(0≤x≤0.3)samples were fabricated by combining sol-gel process with spark plasma sintering(SPS).Y^3+substitution for Ca^2+simultaneously increased the Seebeck coefficient and reduced the thermal *** latter was attributed to the increase in lattice anharmonicity,structural distortion,and grain boundary area,which enhanced the phonon ***2.7Y0.3Co4 O9+δshowed the largest dimensionless figure-of-merit(ZT=0.194)at 1073 K because it had the largest Seebeck coefficient and the lowest thermal *** ZT value was 55%larger than that of undoped Ca3 Co4 O9(0.125 at 1073 K).Therefore,Y^3+substitution,sol-gel powder synthesis,and SPS are highly effective for enhancing the thermoelectric prope rties of Ca_(3)Co_(4)O_(9).

关键词： Electrical conductivity Ca_(3)Co_(4)O_(9) Thermoelectric properties Seebeck coefficient Thermal conductivity Spark plasma sintering

A facile one-step approach to hierarchically assembled core-shell-like MnO2@MnO2 nanoarchitectures on carbon fibers： An efficient and flexible electrode material to enhance energy storage

在线全文

学校读者我要写书评

暂无评论

Nano Research 2016年第5期9卷 1507-1522页

作者： Goli Nagaraju Yeong Hwan Ko Sung Min cha Sang Hyuk Im Jae Su Yu Department of Electronics and Radio Engineering Institute for Wearable Convergence Electronics Kyung Hee University 1732 Deogyeong-daero Giheung-gu Yongin-si Gyeonggi-do 446-701 Republic of Korea Functional Crystallization Center (ERC) Department of Chemical Engineering Kyung Hee University 1732 Deogyeong-daeroGiheuncl-qu Yonqin-si Gyeonqqi-do 446-701 Republic of Korea

Hierarchical core-shell-like MnO2 nanostructures （NSs） were used to anchor MnO2 hexagonal nanoplate arrays （HNPAs） on carbon cloth （CC） fibers. The NSs were prepared by a novel one-step electrochemical deposition method. Under an external cathodic voltage of -2.0 V for 30 min, hierarchical core-shell-like MnO2-NS-decorated MnO2 HNPAs （MnO2 NSs@MnO2 HNPAs） were uniformly grown on CC with reliable adhesion. The phase purity and morphological properties of the samples were characterized by various physicochemical techniques. At a constant external cathodic voltage, growth of MnO2 NSs@MnO2 HNPAs on CC was carried for different time periods. When utilized as a flexible, robust, and binder-free electrode for pseudocapacitors, the hierarchical core-shell-like MnO2 NSs@MnO2 HNPAs on CC showed clearly enhanced electrochemical properties in 1 M Na2SO4 electrolyte solution. The results indicate that the MnO2 NSs@MnO2 HNPAs on CC have a maximum specific capacitance of 244.54 F/g at a current density of 0.5 A/g with excellent cycling stability compared to that of bare MnO2 HNPAs on CC （112.1 F/g at 0.5 A/g current density）. We believe that the superior charge storage performance of the pseudocapacitive electrode can be mainly attributed to the hierarchical MnO2 NSs@MnO2 HNPAs building blocks that have a large specific surface area, offering additional electroactive sites for efficient electrochemical reactions. The facile and single-step approach to growth of hierarchical pseudocapacitive materials on textile based electrodes opens up the possibility for the fabrication of high-performance flexible energy storage devices.

关键词： manganese oxide hierarchical structures carbon cloth electrochemical deposition energy storage properties

Fun learning activities for modern foreign languages

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Fun learning activities for modern foreign languages

Chitosan and β-cyclodextrin Microspheres as Pulmonary Sustained Delivery Systems

作者： Hunton Jake. Evans les.

来源：南通市图书馆图书评论

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2008年第4期23卷 541-546页

作者： ZHANG Weifen CHEN Xiguang LI Piwu HE Qiangzhi ZHOU Huiyun cha Dongsu College of Marine Life Science Ocean University of China Qingdao 266003 China Shandong Academy of Food and Fermentation Industries Jinan 250013 China Graduate School of Biotechnology Korea University Seoul 136-701 Korea Depantment of Pharmacy Weifang Medical University Weifang 261042 China

Chitosan and β-cyclodextrin were used to prepare microspheres with theophylline for pulmonary delivery by spray drying method. The characteristics, mucociliotoxicity, permeation rate and drug release were studied. The drug entrapments of microspheres Ⅰ, Ⅱ and Ⅲ were from 35.70% to 21.09% and 13.33%, while yields and encapsulation efficiencies were higher than 45% and about 90% respectively. The microspheres possessed low tap densities （0.34-0.48 g/cm^3）, appropriate diameters （3.35-3.94 μm） and theoretical aerodynamics diameters （2.20-3.04 μm）. SEM images showed the microspheres were spherical with smooth or wrinkled surface surfaces. FT-IR demonstrated theophylline had formed hydrogen bonds with chitosan and fl-cyclodextrin. The microspheres could effectively reduce the ciliotoxicity and easy to penetrate the memberine. The in vitro release of the microspheres was related to the ratio of drug/polymer and microspheres Ⅱ had a prolong release, providing the release of 72.00% in 12 h. The results suggestes that chitosan/β-cyclodextrin microspheres Ⅱ are a promising carrier as sustained release for pulmonary delivery.

关键词： theophylline chitosan spray-drying microspheres pulmonary delivery

Predicting the Rainfall-Triggered Landslides in a Forested Mountain Region Using TRIGRS Model

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2010年第1期7卷 83-91页

作者： Dongyeob KIM Sangjun IM Sang Ho LEE Youngjoo HONG Kyung-Sub cha Dept. of Forest Sciences Seoul National University Dept. of Forest Sciences Research Institute for Agriculture & life sciences Seoul National University Civil Engineering Team DaeWoo E&C Suwon 440-210 Korea

Landslides are natural disasters which can pose a serious threat to human and property in many areas around the world. The Transient Rainfall Infiltration and Grid-based Regional Slope-stability (TRIGRS) model was used to investigate the rainfall-induced shallow landslides in a forested mountain region, Korea. Various input data for TRIGRS model include time-varying rainfall, topographic characteristics, soil depth, material strength, and hydraulic properties. A series of calculations were conducted in determining the slope stability over the Jangheung region in Korea during the storm occurred on August 6, 1998. The results show that TRIGRS model captured about 64.1% of landslides that were extracted from the IKONOS2 imageries. The model demonstrated how the factor of safety changed with time during a storm considering both the transient and spatial responses of pore water pressure in its slope stability calculation.

关键词： TRIGRS landslides IKONOS2 safetyfactor slope stability Korea

控释掺混肥料一次性基施对热带地区水稻产量及氮肥利用效率的影响

在线全文

学校读者我要写书评

暂无评论

福建农业学报 2024年第7期39卷 766-774页

作者：杨红竹黄艳艳刘海林林清火茶正早罗微中国热带农业科学院橡胶研究所/中国热带农业科学院土壤肥料研究中心/省部共建国家重点实验室培育基地-海南省热带作物栽培生理学重点实验室海南海口571101 儋州橡胶林土壤环境海南省野外科学观测研究站海南儋州571737

【目的】探究控释掺混肥及减氮处理对热带地区水稻产量及氮肥利用效率的影响,以期促进控释掺混肥料在热带地区水稻栽培中的科学施用及推广应用。【方法】以控释掺混肥料为试验材料,在海南省屯昌县枫木镇和儋州市东成镇开展大田试验,设... 详细信息

【目的】探究控释掺混肥及减氮处理对热带地区水稻产量及氮肥利用效率的影响,以期促进控释掺混肥料在热带地区水稻栽培中的科学施用及推广应用。【方法】以控释掺混肥料为试验材料,在海南省屯昌县枫木镇和儋州市东成镇开展大田试验,设置常规施肥(分3次施肥)、控释掺混肥料一次性基施及其减氮10%和减氮20%处理,测定双季稻产量、氮素吸收及氮肥利用效率。【结果】等氮条件下,控释掺混肥料一次性基施能够促进水稻氮素吸收、干物质累积,提高水稻产量和氮肥利用效率;与常规分次施肥相比,水稻产量提高7.43%~22.84%,地上部干物质累积量提高8.22%~22.39%,氮素累积量提高12.19%~32.06%,氮肥利用率提高31.67%~75.65%,且均差异显著(除东成早稻产量外)。而在减氮10%~20%条件下,控释掺混肥一次性基施也能提高或不显著降低水稻产量、干物质累积量和氮素累积量,对氮肥利用率也具有一定提升效果。【结论】控释掺混肥一次性基施可提高水稻产量及肥料氮肥利用率,减氮10%~20%仍能获得较高产量,是热带地区水稻轻简化施肥和减氮增效的有效途径。

关键词：控释掺混肥料一次性施用水稻热带地区产量

Management of sub-5mm rectal carcinoids with lymph node metastases

在线全文

学校读者我要写书评

暂无评论

Gastroenterology Report 2015年第4期3卷 350-354,I0002页

作者： James Wei Tatt Toh Christopher Henderson Takako Eva Yabe Evonne Ong Pierre chapuis les Bokey Department of General Surgery Liverpool HospitalLiverpoolNew South Wales(NSW)Australia Department of Pathology Liverpool HospitalLiverpoolNSWAustralia South West Clinical School University of New South WalesSydneyNSWAustralia Department of Colorectal Surgery Concord HospitalSydneyNSWAustralia Department of Colorectal Surgery Liverpool HospitalLiverpoolNSWAustralia

Minute(<5mm)and small(5-10mm)rectal carcinoids discovered during colonoscopy are generally considered to be non-aggressive,and the management and surveillance of patients with this entity are usually *** present the case of a 61-year-old Chinese female with multiple sub-5mmcarcinoid tumours in the rectum without any computed tomography(CT)evidence of lymph node or distant *** underwent an ultra-low anterior resection for a sessile rectal polyp with the histological appearance of a moderately differentiated *** foci of minute carcinoids in the rectum and perirectal lymph node metastastic spread from the carcinoid tumours were also discovered on *** were no lymph node metastases originating from *** case report and review of the literature suggests that minute rectal carcinoids are at risk of metastasizing and that these patients should be investigated for lymph node and distant metastatic spread with CT and somatostatin receptor scintigraphy or its equivalent,as this would influence prognosis and surgical management of these *** relating to lymphovascular invasion,perineural invasion,high Ki-67,mitotic rate,depth of tumour invasion,central ulceration,multifocal tumours and size are useful in predicting metastases and may be used in scoring *** alone is not a good predictor of metastastic spread.

关键词： rectal carcinoid lymph node metastases tumour size

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

代谢组学揭示茶树嫁接黄酮类物质代谢通路

北方园艺 2024年第4期 1-7页

作者：胡志宏周泳臣茶凤官何亚梅王艳燕高峻百色市茶业发展中心广西百色533000 云南农业大学茶学院云南昆明650100

以茶树品种“云桃”嫁接前后的一芽二叶为试材,采用代谢组学方法,研究了茶树嫁接过程中黄酮类物质的代谢机制,以期为深入探索茶树嫁接的黄酮代谢途径提供参考依据。结果表明:未经过嫁接的“云桃”和嫁接后的接穗“云桃”共检测到804个... 详细信息

以茶树品种“云桃”嫁接前后的一芽二叶为试材,采用代谢组学方法,研究了茶树嫁接过程中黄酮类物质的代谢机制,以期为深入探索茶树嫁接的黄酮代谢途径提供参考依据。结果表明:未经过嫁接的“云桃”和嫁接后的接穗“云桃”共检测到804个代谢物,其中黄酮类代谢物有213个。经过嫁接后,“云桃”中有25个黄酮类代谢物含量增加,9个含量减少。与黄酮类差异代谢物相关的富集通路主要有花青素生物合成、类黄酮生物合成、异黄酮生物合成、黄酮和黄酮醇生物合成。

关键词：代谢组茶树嫁接黄酮

在线全文

学校读者我要写书评

暂无评论

基于NTRU格上非球型离散高斯采样的优化

广州大学学报（自然科学版） 2024年第2期23卷 57-64页

作者：柴惠哲唐春明贾惠文广州大学数学与信息科学学院广东广州510006

随着量子计算机的飞速发展,后量子密码成为研究热点。格密码因性能均衡、安全基础牢靠,以及功能丰富等特点成为后量子密码中的主流。原像采样是格密码中的核心算法,被广泛应用于诸多高级密码方案的构造,格上Hash-and-Sign数字签名是最... 详细信息

随着量子计算机的飞速发展,后量子密码成为研究热点。格密码因性能均衡、安全基础牢靠,以及功能丰富等特点成为后量子密码中的主流。原像采样是格密码中的核心算法,被广泛应用于诸多高级密码方案的构造,格上Hash-and-Sign数字签名是最简单、最直接的应用。从技术上原像采样算法分为GPV型和Peikert型,前者的特点是输出质量高,但算法通常只能串行执行;后者支持并行运算,但输出质量较差。文章将非球面高斯技术应用于NTRU格上的Peikert型采样算法,旨在提升其效率。具体选取了两种参数模式,和原始NTRU格上的Peikert型采样算法相比,模式1可以提高基于该采样算法数字签名的安全强度并降低签名尺寸;模式2在不降低安全性的前提下,可以进一步降低签名尺寸。实验结果表明,在模式1中,安全性提升约18%~20%,签名尺寸降低约15%;模式2保持安全性不变,但是签名尺寸降低约30%~35%。

关键词：格密码 NTRU格非球面高斯采样