Submicron Ti(C,N)-based cermets with improved microstructure using high-energy milled and subsequent heat-treated ultrafine Ti(C,N) powders
作者：
Xie, Dan;Shang, Kepeng;Yi, Zhonghuai;Xiong, Huiwen;Li, Zhiyou;...
期刊：
Ceramics International ,2023年49(3):4064-4073 ISSN：0272-8842
通讯作者：
Gan, Xueping(ganxueping@csu.edu.cn);Xiong, Huiwen(huiwenxiong@csu.edu.cn)
作者机构：
[Gan, Xueping; Xie, Dan; Zhou, Kechao; Li, Zhiyou; Xiong, Huiwen; Shang, Kepeng; Yi, Zhonghuai] Cent South Univ, State Key Lab Powder Met, Changsha 410083, Hunan, Peoples R China.;[Xie, Dan] Hunan City Univ, Coll Mat & Chem Engn, All Solid State Energy Storage Mat & Devices Key L, Yiyang, Peoples R China.
通讯机构：
[Huiwen Xiong; Xueping Gan] S;State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan, 410083, China
关键词：
Ti(C;N)-based cermet;High energy milling;Ultrafine;Core -rim grain
摘要：
Ti(C,N)-based cermets with ultrafine or submicron black core-rim grains are attracting candidates for high-quality tools and dies, due to their high hardness and strength. However, high chemical activity of ultrafine Ti(C,N) powders lead to the increased instability and difficulty to control the sintering process, since the denitrification and interface diffusion are accelerated during the solid-state reaction. Based on this, owing to the unrealized commercial ultrafine-grade powders, ultrafine Ti(C,N) powders with an average grain size around 150 nm, low oxygen content and few dislocations are fabricated via the high-energy ball milling and subsequent heat treatment of commercial micron Ti(C,N) powders. Related morphology evolution, microstructure and composition of the ultrafine Ti(C,N) powders are investigated. Dense submicron Ti(C,N)-based cermets with grain size of 0.62 μm and uniform core-rim phases are successfully prepared by using the as-fabricated ultrafine Ti(C,N) powders. Compared to cermets via the conventional high-energy milling route, submicron Ti(C,N)-based cermets exhibit higher hardness of 1750 ± 40 N/mm2, bending strength of 1960 ± 135 MPa, and satisfactory fracture toughness of 9.2 MPa m1/2, owing to smaller grain size, uniform microstructure and partial black core-rim grains. © 2022
语种：
英文
展开
Nano TiC modified Ti(C,N)-based cermets with weakened rim-binder interfaces
作者：
Xie, Dan;Gan, Xueping;Xiong, Huiwen;Li, Zhiyou;Zhou, Kechao
期刊：
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing ,2022年845:143194 ISSN：0921-5093
通讯作者：
Huiwen Xiong
作者机构：
[Gan, Xueping; Xie, Dan; Zhou, Kechao; Li, Zhiyou; Xiong, Huiwen] Cent South Univ, State Key Lab Powder Met, Changsha 410083, Hunan, Peoples R China.;[Xie, Dan] Hunan City Univ, Coll Mat & Chem Engn, Yiyang 413000, Hunan, Peoples R China.
通讯机构：
[Huiwen Xiong] S;State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan, 410083, China
关键词：
Bending strength;Fracture toughness;Morphology;Sintering;Tensile strength;Titanium carbide;Ar pressures;Core-rim structures;Diffusion-controlled;Metal-ceramic interface;Nano TiC;Nitrogen pressure;Ti(C,N)-based cermet;TiC powders;Ultra-fines;Ultrafine;Cermets
摘要：
In order to solve the problems of high internal stress of core-rim structure, and denitrification behavior of Ti(C, N)-based cermets, nano TiC powders were adopted to promote the diffusion-controlled formation of inner rims and to modify the metal-ceramic interfaces. Based on this, Ti(C,N)-based cermets with 0–8 wt% nano TiC were prepared via solid-state nitrogen-pressure sintering and subsequently Ar-pressure HIP sintering. Nano TiC refined the microstructure and resulted in more white core-rim phase with thicker rims, and ultrafine rimless Ti(C,N). Nano TiC greatly affected the rim-binder interfaces via shifting the equilibrium crystal morphology of (Ti,M) (C,N) in Ni–Co from cubic to octahedron. With the increasing nano TiC content, the orientation relationship of rim-binder interface changed from (200)rim//(111)binder to (111)rim//(111)binder, and the interface strain increaseds. Cermets with {200} rim-binder interface exhibited high bending strength but low fracture toughness and tensile strength, owing to the high bonding strength between rim and binder. Otherwise, weakening strength of the rim-binder interface could enhance the toughness via the breaking of ceramic-binder boundaries. A promising route for preparing Ti(C,N)-based cermets with satisfactory mechanical properties was put forward, via adjusting the rim-binder interfaces. © 2022 Elsevier B.V.
语种：
英文
展开
Dense TiN-Ni cermets with improved sinterability, microstructure, and mechanical properties using Ni-coated TiN powders
作者：
Xie, Dan;Xiong, Huiwen* ;Wu, Yuxue;Gan, Xueping* ;Li, Zhiyou;...
期刊：
International Journal of Applied Ceramic Technology ,2021年18(3):781-791 ISSN：1546-542X
通讯作者：
Xiong, Huiwen;Gan, Xueping
作者机构：
[Gan, Xueping; Xie, Dan; Zhou, Kechao; Li, Zhiyou; Xiong, Huiwen; Wu, Yuxue; Gan, XP] Cent South Univ, State Key Lab Powder Met, Changsha 410083, Peoples R China.;[Xie, Dan] Hunan City Univ, Coll Mat & Chem Engn, All Solid State Energy Storage Mat & Devices Key, Yiyang, Peoples R China.
通讯机构：
[Xiong, HW; Gan, XP] C;Cent South Univ, State Key Lab Powder Met, Changsha 410083, Peoples R China.
关键词：
Core-shell structures;Electroless plating;Microstructure;Ni-coated TiN composite powders;TiN-Ni cermets
摘要：
<jats:title>Abstract</jats:title><jats:p>To solve the poor sinterability and wettability between TiN ceramic and pure metal via using coated composite powders, dense TiN‐Ni cermets with uniform microstructure and fine grains were developed at a low sintering temperature of 1300℃ in this work. TiN powders were firstly activated in a strong acid solution, in order to achieve a step‐like surface; Ni‐coated TiN powders showed an uniform and controllable morphology. Two types of TiN‐Ni cermets based on conventional milled powders and Ni‐coated TiN composite powders were fabricated by spark plasma sintering (SPS), and used for the comparison concerning the sintering behavior, microstructure and related mechanical properties. Results showed that Ni‐coated TiN composite powders helped to improve the sinterability between ceramic and metal, which is rather beneficial to obtain dense TiN‐Ni cermets with homogeneous microstructure and high mechanical properties. Compared to those of conventional TiN‐Ni, the relative density, Rockwell hardness and fracture toughness increased from 84.9% to 96.6%, 80.2 to 84.3, and 10.2MPa·m<jats:sup>1/2</jats:sup> to 14.7MPa·m<jats:sup>1/2</jats:sup>, with a rather low sintering temperature of 1300 ℃, respectively.</jats:p>
语种：
英文
展开
“雨课堂+翻转课堂”的物理化学实验微课教学
作者：
肖谷清;王姣亮;谢丹;孟秋冬
期刊：
化工时刊 ,2021年35(11):39-41 ISSN：1002-154X
作者机构：
[肖谷清; 王姣亮; 谢丹; 孟秋冬] 湖南城市学院材料与化学工程学院
关键词：
物理化学实验;雨课堂;翻转课堂;微课
摘要：
为了解决物理化学实验教学的两个困境:物理化学实验原理抽象、实验需现学现用的仪器多,提出"雨课堂+翻转课堂"的物理化学实验微课教学式。在物理化学实验原理、仪器使用方法这两个学习困难处,设计制作微课。采用"雨课堂+翻转课堂"教学模式,物理化学实验课前将微课教学视频上传到雨课堂平台,将传统的"教师实验课堂讲解"内容作为学生的预习任务完成;课堂解决学生提出的物理化学实验中的问题和完成实验任务;课后及时总结。与传统物理化学实验教学比较,采用"雨课堂+翻转课堂"的实验微课教学,能解决物理化学实验的教学困境,提升学生的学习效果。
语种：
中文
展开
黑茶中茶多酚的提取及其含量测定方法的研究进展
作者：
彭映林;谢丹;李媛;张劲
期刊：
广东化工 ,2019年46(19):110-111,138 ISSN：1007-1865
作者机构：
[谢丹; 彭映林; 张劲; 李媛] 湖南城市学院
关键词：
茶多酚;黑茶;提取;测定方法;含量
摘要：
茶多酚具有抗氧化、降血脂、降血糖、抗辐射等多种功能,在食品、医药、日化、保健等方面具有广泛的应用前景。本文综述了目前常用的几种黑茶中茶多酚的提取及含量测定技术,并对这些方法进行了阐述和比较,最后对茶多酚的提取及含量测定方法研究前景进行了展望。
语种：
中文
展开
含多羟基化合物的改性聚苯乙烯微球对Pb2+的吸附性能研究
作者：
齐风佩;胡一凡;欧盼霖;谢丹
期刊：
湖南城市学院学报(自然科学版) ,2019年28(04):65-69 ISSN：1672-7304
作者机构：
湖南城市学院 材料与化学工程学院,湖南 益阳,413000;[胡一凡; 齐风佩; 谢丹; 欧盼霖] 湖南城市学院
关键词：
席夫碱型螯合树脂;吸附性能
摘要：
以氯甲基化交联聚苯乙烯（CMCPS）微球为起始原料,与对羟基苯甲醛（HBA）发生反应,制得醛基化改性聚苯乙烯微球（ALCPS）,然后再将ALCPS与氨基葡萄糖盐酸盐发生缩合反应,制得席夫碱型螯合树脂AGCPS微球.探究了该树脂对铅离子的吸附性能,测试不同的pH、吸附时间、吸附温度、铅离子溶液的浓度对吸附性能的影响.结果表明:EDTA螯合树脂对镉离子的吸附量随pH值的增大而降低;随吸附时间的延长而增强,然后趋于平缓;随温度升高而增大;随初始离子溶液浓度的增大而不断增强.且其吸附过程符合Langmuir等温吸附方程和Lagergren一级动力学方程.
语种：
中文
展开
基于石墨烯分子印迹电化学传感器测定芦丁
作者：
谢丹;龙立平;刘蓉;钟桐生;李媛;...
期刊：
分析科学学报 ,2017年33(4):545-548 ISSN：1006-6144
作者机构：
[谢丹; 龙立平; 刘蓉; 钟桐生; 李媛; 唐桥亭] 湖南城市学院材料与化学工程学院, 湖南, 益阳, 413000
关键词：
分子印迹传感器;循环伏安法;石墨烯;芦丁
摘要：
将石墨烯(GR)滴涂至裸Au电极表面,并以邻氨基酚为功能单体,芦丁为模板分子,制备了芦丁分子印迹膜电化学传感器,利用循环伏安法(CV)和差分脉冲伏安法(DPV)对制得的传感器进行了电化学性能研究,并且对制备条件和测定条件进行了优化。结果表明,与裸Au电极相比,该GR修饰的Au电极在[Fe(CN)_6]~(3-)/~(4-)溶液中峰电流明显增大,显著提高了芦丁分子印迹传感器的灵敏度。在最优实验条件下,基于 GR分子印迹电化学传感器在4. 40×10~(-6)~2. 80×10~(-4) mol/L范围内呈良好的线性关系,检测限为1.46×10~(-6) mol/L。用该传感器测定了黑茶中芦丁的含量,获得较好结果。
语种：
中文
展开
化学振荡法测定黑茶中茶多酚的含量
作者：
阙百超;姜晓;谭敏;唐也;谢丹
期刊：
湖南城市学院学报(自然科学版) ,2017年26(5):74-78 ISSN：1672-7304
作者机构：
湖南城市学院 材料与化学工程学院,湖南 益阳,413000;[谢丹; 唐也; 姜晓; 阙百超; 谭敏] 湖南城市学院
关键词：
茶多酚含量;没食子酸丙酯;黑茶;B-Z振荡
摘要：
本实验建立葡萄糖-丙酮-硫酸锰-溴酸钾-硫酸的B-Z振荡反应体系,考察没食子酸丙酯及黑茶茶多酚提取液对振荡体系的扰动﹒实验结果显示：没食子酸丙酯的浓度在一定范围内与振荡体系振幅的改变量（ΔE）呈现线性关系,其线性方程为ΔE=57.242 59×lnc＋295.626 59,线性范围0.025 g/L~0.225 g/L,检出限为6.25×10-3 g/L;另外利用该振荡体系对黑茶提取液中的茶多酚进行测定,其结果与紫外-可见分光光度度法测定结果相近;同时分析了茶多酚对葡萄糖振荡体系扰动的振荡机理﹒利用此体系测定黑茶茶多酚含量,成本低、耗时短、操作简单。
语种：
中文
展开
黑茶的电化学指纹图谱研究
作者：
谢丹;龙立平;王姣亮;梁明
期刊：
湖南城市学院学报(自然科学版) ,2014年23(1):36-39 ISSN：1672-7304
作者机构：
湖南城市学院化学与环境工学院,湖南益阳,413000;[谢丹; 龙立平; 梁明; 王姣亮] 湖南城市学院
关键词：
振荡反应;黑茶;碘酸钾
摘要：
采用振荡技术,研究了黑茶-丙酮-溴酸钾-硫酸锰-硫酸的振荡反应新体系的振荡图谱.测定了不同浓度,不同温度下黑茶的振荡反应图谱,考察了添加物碘酸钾对振荡行为的影响,并探索了黑茶的最佳饮用条件.实验结果表明:黑茶振荡体系诱导期表观活化能为Ein=96.919 kJ/mol,振荡周期平均活化能为Ep=64.275 kJ/mol,其最佳饮用条件为浸泡温度100℃、浸泡时间8 min、采用蒸煮茶叶或泡黑茶粉末的方式.这为黑茶制备黑茶饮料以及将黑茶入药的研究提供了一定的指导意义.
语种：
中文
展开
Cu2+-selective “Off–On” chemsensor based on the rhodamine derivative bearing 8-hydroxyquinoline moiety and its application in live cell imaging
作者：
Wang, Jiaoliang;Long, Liping* ;Xie, Dan;Song, Xiaofeng
期刊：
Sensors and Actuators B-Chemical ,2013年177:27-33 ISSN：0925-4005
通讯作者：
Long, Liping
作者机构：
[Wang, Jiaoliang; Xie, Dan; Song, Xiaofeng; Long, Liping] Hunan City Univ, Coll Chem & Environm Engn, Yiyang 413000, Hunan, Peoples R China.
通讯机构：
[Long, Liping] H;Hunan City Univ, Coll Chem & Environm Engn, Yiyang 413000, Hunan, Peoples R China.
关键词：
Binding;Copper(II);Fluorescence chemsensor;Imaging
摘要：
A rhodamine-based fluorescence chemsensor bearing the 8-hydroxyquinoline unit is developed as a reversible turn-on chemosensor for Cu<sup>2+</sup>. It exhibits a highly sensitive fluorescent response toward Cu<sup>2+</sup> in aqueous media with an 80-fold fluorescence intensity enhancement under 10 equiv. of Cu<sup>2+</sup> added. This indicates that the synthesized chemosensor effectively avoided the fluorescence quenching for the paramagnetic nature of Cu<sup>2+</sup> via its strong binding capability toward Cu<sup>2+</sup>. The chemosensor Rh-Q exhibits a dynamic response range for Cu<sup>2+</sup> from 2 ×10<sup>-7</sup> to 5 ×10<sup>-5</sup> M, with a detection limit of 0.19 μM, and good selectivity for Cu<sup>2+</sup> over other heavy and transition metal (HTM) ions in Tris-HCl/EtOH (7:3, v/v, pH 7.4). In addition, the turn-on fluorescent change upon the addition of Cu<sup>2+</sup> is also applied in cell imaging. ©2012 Elsevier B.V. All rights reserved.
语种：
英文
展开
Highly selective fluorescence turn-on sensor for hydrogen sulfide and imaging in living cells
作者：
Wang, Jiaoliang;Long, Liping* ;Xie, Dan;Zhan, Youwen
期刊：
Journal of Luminescence ,2013年139:40-46 ISSN：0022-2313
通讯作者：
Long, Liping
作者机构：
[Wang, Jiaoliang; Xie, Dan; Zhan, Youwen; Long, Liping] Hunan City Univ, Coll Chem & Environm Engn, Yiyang 413000, Hunan, Peoples R China.
通讯机构：
[Long, Liping] H;Hunan City Univ, Coll Chem & Environm Engn, Yiyang 413000, Hunan, Peoples R China.
关键词：
Cell imaging;Chemsensor;CuS;Detection limits;Displacement method;Fluorescence intensities;Fluorescent response;Selective fluorescence;Dynamic response;Fluorescence;Hydrogen sulfide;Negative ions;Sulfur compounds;Sulfur determination;Copper compounds
摘要：
A displacement method of detecting hydrogen sulfide in aqueous media based on complex L-Cu ensemble is developed. Once combined with Cu2+, complex L-Cu displayed high specificity for sulfide anion. Among the various anions, only sulfide anion induce the revival of fluoresecence of compound L, which is quenched by Cu2+, resulting in turn-on type sensing sulfide anion. Complex L-Cu exhibits a highly sensitive fluorescent response toward S2- by releasing compound L to give a remarkable change with 20-fold fluorescence intensity enhancement under 2 equivalent of S2- added in Tris-HCl/ DMF (20 mM, 6/4, v/v), and also exhibits a dynamic response range for S2- from 5×10-7 to 5×10-6 M, with a detection limit of 0.18 μM. In addition, the turn-on fluorescent change upon the addition of S2- is also applied in cell imaging.© 2013 PublishedbyElsevierB.V.
语种：
英文
展开
三组分铜铬催化剂催化甘油制备羟基丙酮的研究
作者：
谢丹;李浔;龙立平;肖谷清;林立
期刊：
广州化工 ,2012年40(12):93-95,126 ISSN：1001-9677
作者机构：
湖南城市学院化学与环境学院,湖南益阳,413000;长沙理工大学化学与生物工程学院,湖南长沙,410076;[李浔] 长沙理工大学;[谢丹; 龙立平; 林立; 肖谷清] 湖南城市学院
关键词：
生物质甘油;Cu-Cr-Zn催化剂;羟基丙酮
摘要：
用共沉淀法制备了Cu-Cr-Zn催化剂,考察了Cu/Cr/Zn比、沉淀温度、沉淀时pH值、煅烧温度等制备条件对甘油制备羟基丙酮的影响,并对催化剂进行了表征。结果表明：共沉淀法制备Cu-Cr-Zn催化剂具有较高的催化活性,而且其稳定性和再生能力较好,适宜催化剂制备条件为：Cu/Cr/Zn比为1∶1∶0.5,沉淀温度为70℃,沉淀时pH值为8.0,煅烧温度为400℃,羟基丙酮的选择性可达到90.2%。
语种：
中文
展开
Fast responsive fluorescence turn-on sensor for Cu2+ and its application in live cell imaging
作者：
Wang, Jiaoliang* ;Li, Hao;Long, Liping;Xiao, Guqing;Xie, Dan
期刊：
Journal of Luminescence ,2012年132(9):2456-2461 ISSN：0022-2313
通讯作者：
Wang, Jiaoliang
作者机构：
[Wang, Jiaoliang; Xie, Dan; Xiao, Guqing; Li, Hao; Long, Liping] Hunan City Univ, Coll Chem & Environm Engn, Yiyang 413000, Peoples R China.
通讯机构：
[Wang, Jiaoliang] H;Hunan City Univ, Coll Chem & Environm Engn, Yiyang 413000, Peoples R China.
关键词：
Aqueous media;Bio-imaging;Color changes;Fast responsive;Fluorescent sensors;Image;Kinetic assay;Live-cell imaging;Naked-eye;Real time tracking;Hydrolysis;Sensors;Transition metal compounds;Transition metals;Fluorescence
摘要：
A new effective fluorescent sensor based on rhodamine was synthesized, which was induced by Cu 2 in aqueous media to produce turn-on fluorescence. The new sensor 1 exhibited good selectivity for Cu 2 over other heavy and transition metal (HTM) ions in H 2O/CH 3CN(7:3, v/v). Upon addition of Cu 2, a remarkable color change from colorless to pink was easily observed by the naked eye, and the dramatic fluorescence turn-on was corroborated. Furthermore, kinetic assay indicates that sensor 1 could be used for real-time tracking of Cu 2 in cells and organisms. In addition, the turn-on fluorescent change upon the addition of Cu 2 was also applied in bioimaging. © 2012 Elsevier B.V. All rights reserved.
语种：
英文
展开
