期刊文献+
共找到18篇文章
< 1 >
每页显示 20 50 100
基于动态投资的鲁棒契约设计与应用研究
1
作者 甘柳 夏鑫 《系统管理学报》 CSSCI CSCD 北大核心 2024年第1期230-239,共10页
基于动态投资理论进行波动率模糊下的鲁棒契约设计,利用鲁棒决策方法和鞅方法给出鲁棒契约的解,并探究委托人波动率模糊对企业投资、证券定价、托宾q、股权溢价以及信用价差的影响。研究发现:鲁棒契约在模糊厌恶的委托人和代理人之间产... 基于动态投资理论进行波动率模糊下的鲁棒契约设计,利用鲁棒决策方法和鞅方法给出鲁棒契约的解,并探究委托人波动率模糊对企业投资、证券定价、托宾q、股权溢价以及信用价差的影响。研究发现:鲁棒契约在模糊厌恶的委托人和代理人之间产生异质信念,从而导致委托人认为企业现金流的波动率高于真实波动率。特别地,当企业接近清算边界或代理人的努力成本较低时,委托人认为的波动率相对更高,并由此形成更严重的投资不足;波动率模糊会降低股东价值、契约规定的投资率以及企业平均q;由波动率模糊厌恶产生的股权溢价和信用价差呈正相关,且两者与企业投资率呈负相关。研究结果有助于把握委托人薪酬契约设计影响机理的内在规律,在深化契约理论研究的同时对公司治理的完善与企业投资效率的提升具有一定的参考价值。 展开更多
关键词 动态投资 鲁棒契约 股权溢价 信用价差
下载PDF
结直肠腺癌中COL9A1蛋白的表达及其临床意义
2
作者 李幸子 龚进 +2 位作者 甘柳 李爽 吴雪辉 《临床与病理杂志》 CAS 2024年第1期31-37,共7页
目的:探讨微环境中Ⅸ型胶原α1(collagen type IX alpha 1 chain,COL9A1)在结直肠腺癌中的表达及其与肿瘤进展的相关性和临床意义。方法:收集2012年1月至2021年1月手术切除的结直肠癌标本408例,采用免疫组织化学检测结直肠腺癌肿瘤组织... 目的:探讨微环境中Ⅸ型胶原α1(collagen type IX alpha 1 chain,COL9A1)在结直肠腺癌中的表达及其与肿瘤进展的相关性和临床意义。方法:收集2012年1月至2021年1月手术切除的结直肠癌标本408例,采用免疫组织化学检测结直肠腺癌肿瘤组织及癌旁正常组织中COL9A1表达,同时检测肿瘤组织中肿瘤蛋白53(tumor protein 53,P53)和错配修复(mismatch repair,MMR)蛋白MLH1、MSH6和PMS2的表达,统计分析COL9A1的表达与各临床病理特征参数的关系,以及与P53突变和MMR状态的相关性,并分析COL9A1阳性表达患者的预后情况。结果:COL9A1在结直肠腺癌肿瘤组织中表达显著低于癌旁正常组织(P<0.001);COL9A1的表达与肿瘤浸润深度、临床分期和肠系膜淋巴结转移有关(χ^(2)=16.943、89.031和84.814;均P<0.001),而与P53突变和MMR状态无关(χ^(2)=0.677、1.260,均P>0.05);Log-rank检验显示COL9A1阴性表达患者的无进展生存期(progression free survival,PFS)和总体生存期(overall survival,OS)显著低于COL9A1阳性表达患者(分别P<0.001,P=0.040)。结论:结直肠腺癌中COL9A1蛋白的表达缺失与肿瘤浸润及转移密切相关,并提示不良预后,这可为结直肠癌预后评估、药物筛选等提供可能的分子标志物和治疗策略。 展开更多
关键词 Ⅸ型胶原α1 结直肠腺癌 临床病理 预后
下载PDF
高质量就业导向下《AutoCAD辅助绘图》课程改革与实践——以广西自然资源职业技术学院国土空间规划与测绘专业为例
3
作者 黄汉山 宁宁 +2 位作者 甘柳 张永霞 张剑波 《林业科技情报》 2024年第3期219-221,共3页
《AutoCAD辅助绘图》是一门基础性、技术性和实践性很强的专业基础课,对国土空间规划与测绘专业的相关专业课的学习起到承上启下的作用,对学生的培养质量至关重要。在当前就业严峻的背景下,该文以高质量就业为导向,从教学目标、课程体... 《AutoCAD辅助绘图》是一门基础性、技术性和实践性很强的专业基础课,对国土空间规划与测绘专业的相关专业课的学习起到承上启下的作用,对学生的培养质量至关重要。在当前就业严峻的背景下,该文以高质量就业为导向,从教学目标、课程体系、教学模式和教学方法等探索《AutoCAD辅助绘图》课程改革与实践,以达到本门课程高质量教学和为其他专业课提供软件技术支撑的目的,整体上提高学生的培养质量,进而提高本专业学生的就业质量。通过实践表明,对该门课程的改革能提高学生的专业水平素养,为学生的高质量就业提供基础。 展开更多
关键词 高质量就业 AUTOCAD 课程 改革
下载PDF
国土空间规划背景下教育专项规划体系研究
4
作者 黄汉山 宁宁 +1 位作者 甘柳 张剑波 《林业科技情报》 2024年第2期251-253,共3页
教育专项规划在保障居民上学的需要方面发挥着重要作用,但随着国土空间规划改革,新的国土空间规划体系对教育专项规划体系也有新的要求。该文以国土空间规划体系为基础,结合教育行业的特色,重新构建教育专项体系。文章提出构建三级四类... 教育专项规划在保障居民上学的需要方面发挥着重要作用,但随着国土空间规划改革,新的国土空间规划体系对教育专项规划体系也有新的要求。该文以国土空间规划体系为基础,结合教育行业的特色,重新构建教育专项体系。文章提出构建三级四类国土空间教育专项规划体系,并结梳理出三级四类的编制内容,为政府部门组织编制教育规划和编制单位编制规划提供参考。 展开更多
关键词 国土空间规划 教育 专项规划 体系
下载PDF
常弹性方差下的动态代理问题及企业融资策略
5
作者 罗鹏飞 甘柳 杨招军 《系统管理学报》 CSSCI CSCD 北大核心 2019年第6期1067-1072,共6页
考虑了常弹性方差下的动态代理问题及企业最优资本结构。假设股东是风险中性的,管理者是风险厌恶的。利用动态规划原理和资产定价理论,给出了动态代理下最优合同的解及企业各未定权益价值。分析了常弹性方差对管理者努力水平及企业融资... 考虑了常弹性方差下的动态代理问题及企业最优资本结构。假设股东是风险中性的,管理者是风险厌恶的。利用动态规划原理和资产定价理论,给出了动态代理下最优合同的解及企业各未定权益价值。分析了常弹性方差对管理者努力水平及企业融资策略的影响。数值结论表明:低弹性方差企业管理者的努力水平较高,但企业债务积压问题严重。此外,企业最优破产水平和杠杆率随弹性方差的增加先递减后增加,同时,高的弹性方差企业具有较高信用风险溢价。 展开更多
关键词 常弹性方差 动态代理 管理者 资本结构 债务积压
下载PDF
早期视网膜分支静脉阻塞患者倍频固体激光治疗对临床疗效及CMT值变化的影响 被引量:5
6
作者 甘柳 杨继礼 孙青 《影像科学与光化学》 CAS 北大核心 2021年第1期111-114,共4页
本文探讨了早期视网膜分支静脉阻塞患者倍频固体激光治疗对临床疗效及黄斑中心视网膜厚度(CMT)值变化的影响。将因视网膜分支静脉阻塞行激光治疗的30例患者纳入激光组,同期行常规治疗的30例患者纳入对照组,对比两组临床疗效、视力、CMT... 本文探讨了早期视网膜分支静脉阻塞患者倍频固体激光治疗对临床疗效及黄斑中心视网膜厚度(CMT)值变化的影响。将因视网膜分支静脉阻塞行激光治疗的30例患者纳入激光组,同期行常规治疗的30例患者纳入对照组,对比两组临床疗效、视力、CMT值变化、眼底荧光血管造影(FFA)检查渗透率及并发症。结果显示,治疗后激光组患者临床治疗总有效率、各个时间点视力变化、CMT值及FFA检查渗透发生率均优于对照组(P<0.05),两组患者均随访6个月,并发症比较差异无统计学意义(P>0.05)。说明早期视网膜分支静脉阻塞患者使用倍频固体激光治疗临床效果显著,可有效提高其视力水平,降低CMT值。 展开更多
关键词 视网膜分支静脉阻塞 倍频固体激光 临床疗效 视力 CMT值
下载PDF
城市文化资本导向下的老城更新策略研究——以桂林市古南门片区为例 被引量:2
7
作者 甘柳 冯兵 《建筑与文化》 2022年第1期155-156,共2页
"十四五"规划明确提出实施城市更新行动,"强化历史文化保护,塑造城市风貌"成为新时代重要的国家战略。文章在分析城市文化资本在老城更新中价值体现及其空间实现可行性的基础上,引入城市文化资本理论,对古南门的城... "十四五"规划明确提出实施城市更新行动,"强化历史文化保护,塑造城市风貌"成为新时代重要的国家战略。文章在分析城市文化资本在老城更新中价值体现及其空间实现可行性的基础上,引入城市文化资本理论,对古南门的城市文化资源进行挖掘和整理,通过构建文化资本生产空间的方式实现文化资源的资本转化,并从营建特色空间与传承地域文化两个角度提出古南门的老城更新策略,为此类文化资源丰富的老城区更新提供思路参考。 展开更多
关键词 老城区 文化资本 古南门 城市更新
下载PDF
Short- and long-term outcomes associated with enhanced recovery after surgery protocol vs conventional management in patients undergoing laparoscopic gastrectomy 被引量:10
8
作者 Yu-Long Tian Shou-Gen Cao +7 位作者 Xiao-Dong liu Ze-Qun Li gan liu Xing-Qi Zhang Yu-Qi Sun Xin Zhou Dao-Sheng Wang Yan-Bing Zhou 《World Journal of Gastroenterology》 SCIE CAS 2020年第37期5646-5660,共15页
BACKGROUND At present,the enhanced recovery after surgery(ERAS)protocol is widely implemented in the field of gastric surgery.However,the effect of the ERAS protocol on the long-term prognosis of gastric cancer has no... BACKGROUND At present,the enhanced recovery after surgery(ERAS)protocol is widely implemented in the field of gastric surgery.However,the effect of the ERAS protocol on the long-term prognosis of gastric cancer has not been reported.AIM To compare the effects of ERAS and conventional protocols on short-term outcomes and long-term prognosis after laparoscopic gastrectomy.METHODS We retrospectively analyzed the data of 1026 consecutive patients who underwent laparoscopic gastrectomy between 2012 and 2015.The patients were divided into either an ERAS group or a conventional group.The groups were matched in a 1:1 ratio using propensity scores based on covariates that affect cancer survival.The primary outcomes were the 5-year overall and cancer-specific survival rates.The secondary outcomes were the postoperative short-term outcomes and inflammatory indexes.RESULTS The patient demographics and baseline characteristics were similar between the two groups after matching.Compared to the conventional group,the ERAS group had a significantly shorter postoperative hospital day(7.09 d vs 8.67 d,P<0.001),shorter time to first flatus,liquid intake,and ambulation(2.50 d vs 3.40 d,P<0.001;1.02 d vs 3.64 d,P<0.001;1.47 d vs 2.99 d,P<0.001,respectively),and lower medical costs($7621.75 vs$7814.16,P=0.009).There was a significantly higher rate of postoperative complications among patients in the conventional group than among those in the ERAS group(18.1 vs 12.3,P=0.030).Regarding inflammatory indexes,the C-reactive protein and procalcitonin levels on postoperative day 3/4 were significantly different between the two groups(P<0.001 and P=0.025,respectively).The ERAS protocol was associated with significantly improved 5-year overall survival and cancer-specific survival rates compared with conventional protocol(P=0.013 and 0.032,respectively).When stratified by tumour stage,only the survival of patients with stage III disease was significantly different between the two groups(P=0.044).CONCLUSION Adherence to the ERAS protocol improves both the short-term outcomes and the 5-year overall survival and cancer-specific survival of patients after laparoscopic gastrectomy. 展开更多
关键词 Enhanced recovery after surgery Conventional management Laparoscopic gastrectomy Short-term outcomes SURVIVAL
下载PDF
股权激励下的高管冒险决策与最优或有薪酬 被引量:3
9
作者 甘柳 杨招军 《运筹与管理》 CSSCI CSCD 北大核心 2022年第1期209-215,共7页
股权类薪酬可导致高管冒险决策,而“内部债”是解决这个问题的可行方案。或有薪酬作为一种新型的“内部债”模式得到了实务界的重视,但如何设计或有薪酬以缓解股权激励下的高管冒险决策尚无理论研究。本文利用动态规划方法,得到高管薪... 股权类薪酬可导致高管冒险决策,而“内部债”是解决这个问题的可行方案。或有薪酬作为一种新型的“内部债”模式得到了实务界的重视,但如何设计或有薪酬以缓解股权激励下的高管冒险决策尚无理论研究。本文利用动态规划方法,得到高管薪酬价值及企业证券价值的显式解;构建委托代理模型,给出薪酬合同激励相容的一个充分条件;并给出了最优合同的数值结果及定量分析。分析表明:与单纯的股权薪酬相比,或有薪酬有效缓解了高管的冒险决策,促使其顾及社会总福利、注重企业长期发展。 展开更多
关键词 股权薪酬 或有薪酬 冒险决策
下载PDF
风险转移下的企业动态投资与资本结构研究 被引量:2
10
作者 甘柳 蔡颖俐 《系统工程学报》 CSCD 北大核心 2021年第2期202-212,288,共12页
考虑到作为内生因素的代理冲突会影响企业资本结构以及信用风险,为此构建了股东风险转移下的代理模型.采用动态规划方法对模型进行求解,并运用数值模拟和参数分析方法,研究股东风险转移以及投资不足所形成的代理问题及其对企业最优资本... 考虑到作为内生因素的代理冲突会影响企业资本结构以及信用风险,为此构建了股东风险转移下的代理模型.采用动态规划方法对模型进行求解,并运用数值模拟和参数分析方法,研究股东风险转移以及投资不足所形成的代理问题及其对企业最优资本结构,信用价差以及托宾q的影响机制.研究结果表明,与传统结构化模型相比,股东风险转移以及投资不足形成的代理冲突可以对"低杠杆之谜"以及"信用价差之谜"做出有效的解释;定义了股东风险转移以及投资不足所形成的代理成本后,发现投资不足形成的代理成本更显著;此外,文中也给出了债务融资下企业平均q和边际q随资本存量以及风险转移强度的变化关系. 展开更多
关键词 风险转移 动态投资 托宾Q 资本结构
下载PDF
Heterobifunctional PEG-grafted black phosphorus quantum dots: “Three-in-One”nano-platforms for mitochondria-targeted photothermal cancer therapy 被引量:1
11
作者 Junyang Qi Yue Xiong +6 位作者 Ke Cheng Qi Huang Jingxiu Cao Fumei He Lin Mei gan liu Wenbin Deng 《Asian Journal of Pharmaceutical Sciences》 SCIE CAS 2021年第2期222-235,共14页
Black phosphorus(BP)nano-materials,especially BP quantum dots(BPQDs),performs outstanding photothermal antitumor effects,excellent biocompatibility and biodegradability.However,there are several challenges to overcome... Black phosphorus(BP)nano-materials,especially BP quantum dots(BPQDs),performs outstanding photothermal antitumor effects,excellent biocompatibility and biodegradability.However,there are several challenges to overcome before offering real benefits,such as poor stability,poor dispersibility as well as difficulty in tailoring other functions.Here,a“three-in-one”mitochondria-targeted BP nano-platform,called as BPQD-PEG-TPP,was designed.In this nano-platform,BPQDs were covalently grafted with a heterobifunctional PEG,in which one end was an aryl diazo group capable of reacting with BPQDs to form a covalent bond and the other end was a mitochondria-targeted triphenylphosphine(TPP)group.In addition to its excellent near-infrared photothermal properties,BPQD-PEG-TPP had much enhanced stability and dispersibility under physiological conditions,efficient mitochondria targeting and promoted ROS production through a photothermal effect.Both in vitro and in vivo experiments demonstrated that BPQD-PEG-TPP performed much superior photothermal cytotoxicity than BPQDs and BPQD-PEG as the mitochondria targeted PTT.Thus this“three-in-one”nanoplatform fabricated through polymer grafting,with excellent stability,dispersibility and negligible side effects,might be a promising strategy for mitochondria-targeted photothermal cancer therapy. 展开更多
关键词 Mitochondria-target Black phosphorus quantum dots Photothermal therapy Heterobifunctional PEG Three-in-one
下载PDF
Dynamic Spectrum Access Scheme of Variable Service Rate and Optimal Buffer-Based in Cognitive Radio
12
作者 Qiang Peng Youchen Dong +2 位作者 Weimin Wu Haiyang Rao gan liu 《Communications and Network》 2013年第3期232-237,共6页
Dynamic spectrum access (DSA) scheme in Cognitive Radio (CR) can solve the current problem of scarce spectrum resource effectively, in which the unlicensed users (i.e. Second Users, SUs) can access the licensed spectr... Dynamic spectrum access (DSA) scheme in Cognitive Radio (CR) can solve the current problem of scarce spectrum resource effectively, in which the unlicensed users (i.e. Second Users, SUs) can access the licensed spectrum in opportunistic ways without interference to the licensed users (i.e. Primary Users, PUs). However, SUs have to vacate the spectrum because of PUs coming, in this case the spectrum switch occurs, and it leads to the increasing of SUs’ delay. In this paper, we proposed a Variable Service Rate (VSR) scheme with the switch buffer as to real-time traffic (such as VoIP, Video), in order to decrease the average switch delay of SUs and improve the other performance. Different from previous studies, the main characteristics of our studying of VSR in this paper as follows: 1) Our study is on the condition of real-time traffic and we establish three-dimension Markov model;2) Using the internal optimization strategy, including switching buffer, optimizing buffer and variable service rate;3) As to the real-time traffic, on the condition of meeting the Quality of Service(QoS) on dropping probability, the average switch delay is decreased as well as improving the other performance. By extensive simulation and numerical analysis, the performance of real-time traffic is improved greatly on the condition of ensuring its dropping probability. The result fully demonstrates the feasibility and effectiveness of the variable service rate scheme. 展开更多
关键词 COGNITIVE Radio Dynamic Spectrum Access Variable Service Rate OPTIMAL BUFFER MARKOV DECISION
下载PDF
Phosphorylcholine polymer nanocapsules prolong the circulation time and reduce the immunogenicity of therapeutic proteins 被引量:13
13
作者 Sheng Liang Yang liu +11 位作者 Xin Jin gan liu Jing Wen Linlin Zhang Jie Li Xubo Yuan Irvin S.Y. Chen Wei Chen Hui Wang Linqi Shi Xinyuan Zhu Yunfeng Lu 《Nano Research》 SCIE EI CAS CSCD 2016年第4期1022-1031,共10页
Protein therap34 wherein therapeutic proteins are delivered to treat disorders, is considered the safest and most direct approach for treating diseases. However, its applications are highly limited by the paucity of e... Protein therap34 wherein therapeutic proteins are delivered to treat disorders, is considered the safest and most direct approach for treating diseases. However, its applications are highly limited by the paucity of efficient strategies for delivering proteins and the rapid clearance of therapeutic proteins in vivo after their administration. Here, we demonstrate a novel strategy that can significantly prolong the circulation time of therapeutic proteins as well as minimize their immunogenicity. This is achieved by encapsulating individual protein molecules with a thin layer of crosslinked phosphorylcholine polymer that resists protein adsorption. Through extensive cellular studies, we demonstrate that the crosslinked phosphorylcholine polymer shell effectively prevents the encapsulated protein from being phagocytosed by macrophages, which play an essential role in the clearance of nanoparfides in vivo. Moreover, the polymer shell prevents the encapsulated protein from being identified by immune cells. As a result, immune responses against the therapeutic protein are effectively suppressed. This work describes a feasible method to prolong the circulation time and reduce the immunogenicity of therapeutic proteins, which may promote the development and application of novel protein therapies in the treatment of diverse diseases. 展开更多
关键词 protein nanocapsule protein delivery protein therapy long-circulation stealth therapeutic
原文传递
Prolonging the plasma circulation of proteins by nano- encapsulation with phosphorylcholine-based polymer 被引量:4
14
作者 Linlin Zhang Yang liu +5 位作者 gan liu Duo Xu Sheng Liang Xinyuan Zhu Yunfeng Lu Hui Wang 《Nano Research》 SCIE EI CAS CSCD 2016年第8期2424-2432,共9页
Short in vivo circulation is a major hindrance to the widespread adoption of protein therapeutics. Protein nanocapsules generated by encapsulating proteins with a thin layer of phosphorylcholine-based polymer via a tw... Short in vivo circulation is a major hindrance to the widespread adoption of protein therapeutics. Protein nanocapsules generated by encapsulating proteins with a thin layer of phosphorylcholine-based polymer via a two-step encapsulation process exhibited significantly prolonged plasma half-life. Furthermore, by constructing nanocapsules with similar sizes but different surface charges and chemistry, we demonstrated a generic strategy for prolonging the plasma half-life of therapeutic proteins. In an in vitro experiment, four types of bovine serum albumin (BSA) nanocapsules were incubated with fetal bovine serum (FBS) in phosphate buffer saline (PBS); the cell uptake by HeLa cells was monitored to systematically evaluate the characteristics of the surface chemistry during drculation. Single positron emission tomography-computed tomography (SPECT) was employed to allow real-time observation of the BSA nanoparticle distribution in vivo, as well as quantification of the plasma concentration after intravenous administration. This study offers a practical method for translating a broad range of proteins for clinical use. 展开更多
关键词 phosphorylcholine-basedpolymer nano-encapsulation function protein delivery protein therapy long-circulation
原文传递
时间偏好不一致下控制权私利与最优股权结构 被引量:5
15
作者 甘柳 杨波 《中国管理科学》 CSSCI CSCD 北大核心 2020年第6期51-62,共12页
引入时间偏好不一致,基于实物期权框架构建控制股东谋取私利的动态模型。运用均衡定价方法,得到不同类型控制股东财富价值的显示表达,并在最优股权结构的基础上给出内生化的投资时机、投资规模以及退出时机所满足的代数方程。研究结果表... 引入时间偏好不一致,基于实物期权框架构建控制股东谋取私利的动态模型。运用均衡定价方法,得到不同类型控制股东财富价值的显示表达,并在最优股权结构的基础上给出内生化的投资时机、投资规模以及退出时机所满足的代数方程。研究结果表明,时间偏好不一致控制股东持有的最优股权比例大都集中于区间20%-30%,且成熟型控制股东较幼稚型控制股东持有更低的最优股权比例。与无代理冲突情形相比,时间偏好不一致控制股东表现出延迟投资,但投资规模随着时间偏好不一致程度的增大而先增后减。最后,在最优股权结构下分析投资者保护程度对控制股东决策的影响,为公司治理提供新的视角。 展开更多
关键词 时间偏好不一致 控制权私利 投资策略 最优股权结构
原文传递
研发项目投资决策与最优政府补贴研究 被引量:4
16
作者 甘柳 李群翅 《中国管理科学》 CSSCI CSCD 北大核心 2023年第2期63-72,共10页
补贴是政府支持企业创新的重要方式之一。在政府采取研发项目资金补贴策略的基础上,构建政府和企业家双方博弈的不确定性投资与融资模型,并给出博弈均衡下最优投资时机、投资成本、融资策略以及最优政府补贴的显式表达式。研究发现企业... 补贴是政府支持企业创新的重要方式之一。在政府采取研发项目资金补贴策略的基础上,构建政府和企业家双方博弈的不确定性投资与融资模型,并给出博弈均衡下最优投资时机、投资成本、融资策略以及最优政府补贴的显式表达式。研究发现企业家的债务协商能力会影响到政府对企业的补贴策略,只有当企业家在债务市场拥有一定议价能力的时候,政府补贴才能有效缓解研发项目的投资不足问题。另外,随着企业收益流的不确定性的增加,均衡下政府补贴出现先增后减的趋势,政府应尽可能根据不同风险的研发项目来采取补贴策略。本文的结论从理论上丰富了已有研发补贴政策的研究,为政府更有针对性实施补贴政策提供有益参考。 展开更多
关键词 研发项目 不确定性投资 协商 融资决策 研发补贴
原文传递
A new oxyapatite red phosphor Eu^(3+)-doped Ca_(3)Y_(7)(BO_(4))(SiO_(4))_(5)O:Synthesis,structure and luminescence properties 被引量:3
17
作者 Tian Tian Wei liu +4 位作者 Qi liu Yan Zhang Yaoqing Chu gan liu Jiayue Xu 《Journal of Rare Earths》 SCIE EI CAS CSCD 2022年第5期709-716,I0002,共9页
A series of new oxyapatite red phosphors Ca_(3) Y_(7)(BO_(4)) (SiO_(4))_(5) O doped with different concentrations of Eu^(3+)were successfully synthesized by high temperature solid state method.The X-ray diffraction(XR... A series of new oxyapatite red phosphors Ca_(3) Y_(7)(BO_(4)) (SiO_(4))_(5) O doped with different concentrations of Eu^(3+)were successfully synthesized by high temperature solid state method.The X-ray diffraction(XRD)Rietveld refinement results show that the structure of the phosphor belongs to space group P6_(3)/m and Eu^(3+)ion replaces Y^(3+)ion.The emission spectrum consists of the characteristic emission peaks corresponding to Eu^(3+)under the excitation of 274 nm and the dominant emission peak is at 614 nm(^(5)D_(0)→^(7)F_(2) of Eu^(3+)).The concentration quenching effect occurs and the optimized Eu^(3+)concentration is 4.0 mol%.The energy level diagram for luminous mechanism is also given and the non-radiative energy transfer mechanism between Eu^(3+)is mainly exchange interaction.The CIE coordinate is close to the ideal red light and the color purity is higher than 99.79%.Moreover,the phosphor exhibits moderate thermal stability because the photoluminescence intensity at 423 K is still maintained at higher than 78.97%of that at room temperature.The internal quantum efficiency of Ca_(3) Y_(7)(BO_(4)) (SiO_(4))_(5) O:4.0 mol%Eu^(3+)phosphor is 58.2%.A red light emitting diode(LED)device based on it can emit bright red light.The CCT values of the device are basically unchanged when driven by various bias current.The results show that Ca_(3) Y_(7)(BO_(4)) (SiO_(4))_(5) O:Eu^(3+)is a new type of oxyapatite red fluorescent material with good comprehensive performances. 展开更多
关键词 Red phosphor Oxyapatite structure Eu3+ions doping LED device Rare earths
原文传递
Up-converted ultraviolet luminescence of Er3+:BaGd2Zn05phosphors for healthy illumination
18
作者 Ya ZHANG Qingzhi CUI +3 位作者 Zhanyong WANG gan liu Tian TIAN Jiayue XU 《Frontiers of Materials Science》 SCIE CSCD 2016年第3期328-333,共6页
Moderate level of exposure to the solar irradiation containing UV component is essential for health care. To incorporate the UV-emitting phosphors into the commercial YAG-based white light-emitting diode introduces th... Moderate level of exposure to the solar irradiation containing UV component is essential for health care. To incorporate the UV-emitting phosphors into the commercial YAG-based white light-emitting diode introduces the possibilities of healthy illumination to individuals' daily lives. 1 mol.% E3*-doped BaGd2ZnO5(BGZ) particles were synthesized via sol-gel method and efficient up-converted luminescence peaked at 380 nm was detected under 480 nm excitation. The mixed phosphors with varied mass ratio of Er3+:BGZ and Ce3+:YAG particles were encapsulated to form LEDs. The study of the LEDs indicated that the introduction of BGZ component favored the enhancement of color-rendering index and the neutralization of the white light emitting. The WLED with the BGZ/YAG ratio of 8:2 was recommendable for its excellent overall white light luminous performances and UV intensity of 84.55 mW/cm2. The UV illumination dose of the WLEDs with mixed YAG and BGZ was controllable by adjusting the ratio, the illumination distance and the illumination time. Er3+:BGZ phosphors are promising UV- emitting phosphors for healthy indoor illumination. 展开更多
关键词 Er3+:BaGd2ZnOs up-converted ultraviolet LED healthy illumination
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部