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Weak wide-band signal detection method based on small-scale periodic state of Duffing oscillator 被引量:3
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作者 Jian Hou Xiao-peng Yan +1 位作者 Ping Li Xin-hong Hao 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第3期205-215,共11页
The conventional Duffing oscillator weak signal detection method, which is based on a strong reference signal, has inherent deficiencies. To address these issues, the characteristics of the Duffing oscillator's phase... The conventional Duffing oscillator weak signal detection method, which is based on a strong reference signal, has inherent deficiencies. To address these issues, the characteristics of the Duffing oscillator's phase trajectory in a small- scale periodic state are analyzed by introducing the theory of stopping oscillation system. Based on this approach, a novel Duffing oscillator weak wide-band signal detection method is proposed. In this novel method, the reference signal is discarded, and the to-be-detected signal is directly used as a driving force. By calculating the cosine function of a phase space angle, a single Duffing oscillator can be used for weak wide-band signal detection instead of an array of uncoupled Duffing oscillators. Simulation results indicate that, compared with the conventional Duffing oscillator detection method, this approach performs better in frequency detection intervals, and reduces the signal-to-noise ratio detection threshold, while improving the real-time performance of the system. 展开更多
关键词 Duffing oscillator weak signal detection stopping oscillation system small-scale periodic state
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THE CLASSIFICATION AND PERIOD OF STATES FOR MARKOV CHAIN IN RANDOM ENVIRONMENT 被引量:11
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作者 胡迪鹤 《Acta Mathematica Scientia》 SCIE CSCD 2005年第1期23-29,共7页
This paper is a continuation of [8]. In Section 1, three kinds of communication are introdnced for two states and the relations among them are investigated. In Section 2, two kinds of period of a state are introdnced ... This paper is a continuation of [8]. In Section 1, three kinds of communication are introdnced for two states and the relations among them are investigated. In Section 2, two kinds of period of a state are introdnced and it is obtained that the period is a 'class property',i.e. two states x and y belong to same class implies the period of x is equal to the period of y. 展开更多
关键词 Markov chain in random environment recurrent state transient state period
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Scientific Investigation on Bronze Swords from Spring-Autumn and Warring States Period
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作者 何堂坤 《Rare Metals》 SCIE EI CAS CSCD 1992年第1期68-73,共6页
1. Introduction The bronze swords were somewhat important in ancient China. Its alloy constituent analysishas been carried out by some scientist with modern technique. Afterwards, a series of work havebeen published. ... 1. Introduction The bronze swords were somewhat important in ancient China. Its alloy constituent analysishas been carried out by some scientist with modern technique. Afterwards, a series of work havebeen published. The main results are: (1) the sword materials are Pb-Sn-bearing bronze with tincontent at 15~19%; (2) it is cast alloy mainly; (3) the rhombus pattern on the sword of Yue King 展开更多
关键词 In Scientific Investigation on Bronze Swords from Spring-Autumn and Warring states period
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Wave Period Distributions in Non-Gaussian Mixed Sea States
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作者 王迎光 《China Ocean Engineering》 SCIE EI CSCD 2013年第6期809-820,共12页
The wave period probability densities in non-Gaussian mixed sea states are calculated by utilizing a transformed Gaussian process method. The transformation relating the non-Gaussian process and the original Gaussian ... The wave period probability densities in non-Gaussian mixed sea states are calculated by utilizing a transformed Gaussian process method. The transformation relating the non-Gaussian process and the original Gaussian process is obtained based on the equivalence of the level up-crossing rates of the two processes. A saddle point approximation procedure is applied for calculating the level up-crossing rates in this study. The accuracy and efficiency of the transformed Gaussian process method are validated by comparing the results predicted by using the method with those predicted by the Monte Carlo simulation method. 展开更多
关键词 wave period mixed sea state NON-GAUSSIAN saddle point approximation Monte Carlo simulation
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ON CRAFT OF SILK “KNITTING” CORDS OF WARRING STATES PERIOD IN JIANGLING
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作者 包铭新 《Journal of China Textile University(English Edition)》 EI CAS 1993年第3期1-7,共7页
Seven pieces of silk braids excavated from Chu Tomb No.1 at M ashan in Jiangling are thoughtto belong to the knitting fabric.Their structures are double-stitched type,with a lining silk on theback side to fix the knit... Seven pieces of silk braids excavated from Chu Tomb No.1 at M ashan in Jiangling are thoughtto belong to the knitting fabric.Their structures are double-stitched type,with a lining silk on theback side to fix the knitted threads;besides the traverse linking structure,there are alsomulti-structures by single jersey combined with traverse linking,the excavators declared.The au-thor of this paper believes that those cords can be classified as some intermediary between theknitwear and the needlework.They have the structure similar to certain kinds of knitting,crochetand embroidery,and can be duplicated through two different methods.The differences and similar-ities between these cords and the traditional hand-knitting or embroidery,as well as their originsare discussed.Photographs of the relic and the duplication are presented. 展开更多
关键词 KNITTING NEEDLE punched fabrics SILK Warring states period Jiangling SILK “knitting” CORD NEEDLE work.
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THE STATE COUNCIL DECIDES TO EXTEND THEIMPORT-DUTY EXEMPTION PERIOD FOR IMPORTS OF EQUIPMENT AND RAW MATERIALS BY ENTERPRISES WITH FOREIGN INVESTMENT
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《大经贸》 北大核心 1997年第4期86-87,共2页
Recently the State Council decided to extend the period ofduty exemption for imports of equipment and raw materials by foreign-invested enterprises below US$30 million.In order to administrate import and export activi... Recently the State Council decided to extend the period ofduty exemption for imports of equipment and raw materials by foreign-invested enterprises below US$30 million.In order to administrate import and export activities in light ofinternational practice and apply a unified, fair and standardizedpolicy toward import duties, the State Council, on December28,1995, decided to reform and adjust the policies of import duties by fairly significant reduction of the overall import tariff leveland elimination of preferences of import-duty exemption for mostimport items, which was also applicable to imports of equipmentand raw materials by foreign-invested enterprises set up since April1st, 1996. At the same time, with a view to maintaining the policycontinuity and relative stability, those enterprises established before March 31, 1996 were allowed an extended duty-exemptionperiod of one to two years for importation of equipment and rawmaterials(referring to construction materials, etc.) if such importswere below the value of their total investments, and for 展开更多
关键词 RAW THE state COUNCIL DECIDES TO EXTEND THEIMPORT-DUTY EXEMPTION period FOR IMPORTS OF EQUIPMENT AND RAW MATERIALS BY ENTERPRISES WITH FOREIGN INVESTMENT US
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A CLOSED-FORM ALGORITHM FOR THE STEADY-STATE RESPONSE OF ELASTIC MECHANISMS
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作者 顾洪波 《Journal of China Textile University(English Edition)》 EI CAS 1990年第3期47-50,共4页
This paper presents a closed-form algorithm for the steady-state response of elastic mecha-nisms. Based on an analytic expression of the initial conditions, the steady-state response can beobtained by just one cycle o... This paper presents a closed-form algorithm for the steady-state response of elastic mecha-nisms. Based on an analytic expression of the initial conditions, the steady-state response can beobtained by just one cycle of integration, thus the algorithm is of high efficiency. The algorithm isthen verified by comparing the computational results with the previously published experimental re-sults. 展开更多
关键词 mechanism ELASTIC analysis algorithm STEADY-state response periodIC COEFFICIENT FUNDAMENTAL matrix.
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Interpretation of Dark Matter and Quark-Gluon Plasma: The Generation of the Periodic Table Elements and Its Phase Diagram: A Novel Millennium Power Plant
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作者 Murad Al Shibli 《Natural Science》 2015年第9期438-458,共21页
This paper presents a novel physical interpretation of the state of matter of the quark-gluon as the most fundamental building blocks in nature. Such a model is derived based on the assumption that dark matter and dar... This paper presents a novel physical interpretation of the state of matter of the quark-gluon as the most fundamental building blocks in nature. Such a model is derived based on the assumption that dark matter and dark energy behave as a perfect ideal fluid at extremely high temperature. By the virtue of Boltzmann constant of the ideal gas law and NASA’s Cosmic Microwave Background Explorer (CMB) which estimate that the space has an average temperature close to 2.7251 Kelvin, then the equivalent mass-energy of the fundamental particle of the dark matter/dark energy is determined. Moreover, assuming a uniform space dark energy/dark matter density, then the critical temperature at which the dark matter has a unity entity per volume is identified as 64 × 1012 K. The calculated critical temperature of the quark-gluon plasma is found to be proportional to the temperature generated by colliding heavy ions at the Relativistic Heavy Ion Collider (RHIC) and European Organization for Nuclear Research (CERN). Moreover, the individual critical temperatures of the quark-gluon plasma matter at which the elements of the Periodic Table are generated are explicitly determined. The generation temperature trend of the elements of the Periodic Table groups and Periods is then demonstrated. Accordingly, the phase diagram of the quark-gluon state matter is proposed. Finally, a new model of quark-gluon power generation plant is proposed and aims to serve humanity with new energy sources in the new millennium. 展开更多
关键词 DARK MATTER DARK Energy QUARK-GLUON Plasma Equation of state periodic TABLE Standard Model
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Periodic Solutions for Functional Differential Inclusion with Nonconvex Right Hand Sides
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作者 吕显瑞 史少云 李晓光 《Northeastern Mathematical Journal》 CSCD 2003年第4期396-406,共11页
In this paper we present a general existence result of periodic solutions for functional differential inclusions with nonconvex right hand sides, by using the asymptotic fixed point theory. In our result, the uniform ... In this paper we present a general existence result of periodic solutions for functional differential inclusions with nonconvex right hand sides, by using the asymptotic fixed point theory. In our result, the uniform boundedness and ultimate boundedness are only assumed to the solutions with bounded initial functions. On the other hand, the dissipativity is sought on a suitable bounded convex subset of the state space of solutions. This becomes difficult for the systems with infinite delay since in this case the subset is probably not forward invariant for the orbits of solutions. These are also considerable even for the usual functional differential equations with infinite delay. As an application, we answer an open problem on the existence of an equilibrium state for multivalued permanent systems. 展开更多
关键词 functional differential inclusion periodic solution PERMANENCE equilibrium state
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反应堆瞬时短周期与反应性引入速率约束问题研究
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作者 朱贵凤 严睿 +3 位作者 邹杨 郁长清 赵学超 郭建 《核技术》 EI CAS CSCD 北大核心 2024年第3期102-108,共7页
核反应堆在反应性引入过程中会出现瞬时短周期现象,可能触发周期保护系统,从而出现非必要停堆问题。瞬时短周期受反应性引入速率影响较大,但同时与当前缓发中子先驱核浓度相关,一般难以量化。本文从点堆方程出发,基于两次保守假设,剥离... 核反应堆在反应性引入过程中会出现瞬时短周期现象,可能触发周期保护系统,从而出现非必要停堆问题。瞬时短周期受反应性引入速率影响较大,但同时与当前缓发中子先驱核浓度相关,一般难以量化。本文从点堆方程出发,基于两次保守假设,剥离出缓发中子先驱核浓度因素,推导出了简洁的瞬时短周期与反应性引入速率约束公式;并验证在该反应性速率约束下,瞬时短周期永远大于目标周期值,可以避免意外触发周期保护问题,为反应堆运行中的控制棒提升速率约束提供了理论依据。 展开更多
关键词 核反应堆 反应堆周期 瞬态 反应性
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Quantum Properties of Two-Dimensional Electron as Invariants of Periodic Confining Potential Transformations
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《材料科学与工程(中英文B版)》 2012年第2期208-211,共4页
关键词 量子特性 二维电子 周期性结构 期限 晶体结构 傅里叶级数 纳米尺寸 量子跃迁
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Phase diagram,correlations,and quantum critical point in the periodic Anderson model
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作者 Jian-Wei Yang Qiao-Ni Chen 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第3期362-367,共6页
Periodic Anderson model is one of the most important models in the field of strongly correlated electrons. With the recent developed numerical method density matriX embedding theory, we study the ground state properti... Periodic Anderson model is one of the most important models in the field of strongly correlated electrons. With the recent developed numerical method density matriX embedding theory, we study the ground state properties of the periodic Anderson model on a two-dimensional square lattice. We systematically investigate the phase diagram away from half filling. We find three different phases in this region, which are distinguished by the local moment and the spin-spin correlation functions. The phase transition between the two antiferromagnetic phases is of first order. It is the so-called Lifshitz transition accompanied by a reconstruction of the Fermi surface. As the filling is close to half filling, there is no difference between the two antiferromagnetic phases. From the results of the spin-spin correlation, we find that the Kondo singlet is formed even in the antiferromagnetic phase. 展开更多
关键词 periodic Anderson model Kondo singlet states density matrix embedding theory
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基于精神情感状况导向的照护模式在重症颅脑损伤术后恢复期患者中的应用 被引量:1
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作者 汤新颜 陈媚珍 吴俊琪 《中国医药导报》 CAS 2024年第6期172-175,共4页
目的 探讨基于精神情感状况导向的照护模式在重症颅脑损伤术后恢复期患者中的应用效果。方法 选取2020年2月至2023年2月湖南中医药高等专科学校附属第一医院100例重症颅脑损伤恢复期患者,以奇偶数法分为对照组和干预组,各50例。对照组... 目的 探讨基于精神情感状况导向的照护模式在重症颅脑损伤术后恢复期患者中的应用效果。方法 选取2020年2月至2023年2月湖南中医药高等专科学校附属第一医院100例重症颅脑损伤恢复期患者,以奇偶数法分为对照组和干预组,各50例。对照组于术后恢复期给予常规护理干预,干预组在对照组的基础上给予基于精神情感状况导向的照护模式干预,干预1个月。比较两组干预前后负面情绪[焦虑自评量表(SAS)及抑郁自评量表(SDS)]、日常生活活动能力[改良Barthel指数(MBI)]及认知功能[蒙特利尔认知评估量表(Mo CA)]。结果 干预后,两组SAS、SDS评分低于干预前,且干预组低于对照组(P<0.05);两组MBI、Mo CA评分高于干预前,且干预组高于对照组(P<0.05)。结论 基于精神情感状况导向的照护模式可改善重症颅脑损伤术后恢复期患者的负面情绪,提高日常生活活动能力和认知功能。 展开更多
关键词 重症颅脑损伤 术后恢复期 精神情感状况 照护模式
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Connotations and Internal Cultural Meanings of Chinese Jade in Chu Culture at Pre-Qin Period
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作者 Li Zhongyuan 《学术界》 CSSCI 北大核心 2016年第6期315-319,共5页
The thesis conducts its analysis fromthe perspective of cultural characteristics of Chu state of Pre-Qin period in ancient China.The culture of Chu,usually focusing on ceremony sacrifice and several other activities,p... The thesis conducts its analysis fromthe perspective of cultural characteristics of Chu state of Pre-Qin period in ancient China.The culture of Chu,usually focusing on ceremony sacrifice and several other activities,presents unique characteristics of the development of Chinese society and culture.Actually,the jade artifact at that time shows cultural features both at artistic and spiritual level and bears prominent cultural connotations like national spirit of solemnness and generosity.Chinese jade of Chu state of Pre-Qin period due to its abundant cultural connotations and meanings,poses to be an essential element of traditional Chinese culture,which shows artistic and national features of traditional jade culture and can directly influence development of modern society and culture. 展开更多
关键词 文化内涵 楚文化 中国 社会文化发展 中华传统文化 玉器 文化特征 民族精神
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“犬”“豚”辨异——兼论勾践生育奖励政策中蕴含的性别观
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作者 叶娇 《台州学院学报》 2024年第1期33-39,共7页
传世名篇《勾践灭吴》中有关生育奖励的措施影响深远,但生男生女分别奖励犬豚的做法却广受争议,颇多分歧。从语言、历史、文化多角度辨析“犬”“豚”之异,明确先秦时期犬、豚同为重要肉食来源,但越人纵狗行猎,在越国,犬的地位高于豚;... 传世名篇《勾践灭吴》中有关生育奖励的措施影响深远,但生男生女分别奖励犬豚的做法却广受争议,颇多分歧。从语言、历史、文化多角度辨析“犬”“豚”之异,明确先秦时期犬、豚同为重要肉食来源,但越人纵狗行猎,在越国,犬的地位高于豚;犬阳豚阴的动物阴阳观念乃汉人习气,并不适用于当时的越国;勾践分别奖励是出于犬、豚的不同文化蕴含,体现的是男尊女卑思想下男女分工的不同。勾践各尽其用的性别观对当今社会亦有借鉴启示意义。 展开更多
关键词 《勾践灭吴》 先秦 越国 生育奖励
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湖北荆州张大冢战国楚墓出土青铜器的成分与金相研究
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作者 胡飞 闻磊 秦颍 《有色金属(冶炼部分)》 CAS 北大核心 2024年第2期127-137,共11页
利用X射线荧光光谱仪(XRF)、金相显微镜对荆州市纪南镇雨台村张大冢战国墓地出土12件青铜器进行成分与金相分析。结果表明,12件青铜器分别为铅锡青铜、锡铅青铜和锡青铜3种材质,铅锡(或锡铅)青铜器普遍含铅量较高,青铜器多以铸造成形,... 利用X射线荧光光谱仪(XRF)、金相显微镜对荆州市纪南镇雨台村张大冢战国墓地出土12件青铜器进行成分与金相分析。结果表明,12件青铜器分别为铅锡青铜、锡铅青铜和锡青铜3种材质,铅锡(或锡铅)青铜器普遍含铅量较高,青铜器多以铸造成形,铜盘均采用热锻加工技术。不同类型及使用功能的器物,其合金成分与金相组织存在明显差异。张大冢墓地作为战国中晚期的楚国下等级贵族家族墓地,出土青铜容器也多为素面薄壁,锈蚀较为严重,但其出土青铜器的合金配比、制作技术及机械性能均展现出战国中晚期楚国工匠已经拥有成熟的青铜合金、铸造以及加工技术,也揭示出当时工匠有意识地在青铜明器与实用器的合金技术上存在区别对待,为全面认识东周时期楚都纪南城青铜冶铸业的发展状况提供科学依据。 展开更多
关键词 楚都纪南城 张大冢战国楚墓 青铜器 合金成分 金相组织
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中原地区战国至西汉墓葬出土陶釜研究
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作者 张亮 秦雪松 《文博》 北大核心 2024年第2期72-79,共8页
本文通过系统聚类分析方法,对中原地区战国至西汉墓葬出土的陶釜进行了类型学研究,认为战国中期陶釜以一种特殊葬俗的形式出现在郑州地区,战国晚期开始陶釜迅速发展,分布范围变广,数量和类型明显增多,包含有郑韩文化、晋文化和秦文化三... 本文通过系统聚类分析方法,对中原地区战国至西汉墓葬出土的陶釜进行了类型学研究,认为战国中期陶釜以一种特殊葬俗的形式出现在郑州地区,战国晚期开始陶釜迅速发展,分布范围变广,数量和类型明显增多,包含有郑韩文化、晋文化和秦文化三大系统。进入汉代,陶釜数量急剧减少,类型单一。陶釜在中原地区的发展历程与秦文化有密切的关系。 展开更多
关键词 陶釜 中原地区 战国 西汉 类型学
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亲情护理服务干预对前列腺增生患者围手术期并发症、心理状态及睡眠质量的影响
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作者 郭姝馨 《世界睡眠医学杂志》 2024年第6期1299-1302,共4页
目的:分析亲情护理服务干预对前列腺增生患者围手术期并发症、心理状态及睡眠质量的影响。方法:选取2019年7月至2022年9月福建医科大学附属第二医院收治的前列腺增生患者101例为研究对象,按照随机数字表法分为对照组(n=50)和观察组(n=5... 目的:分析亲情护理服务干预对前列腺增生患者围手术期并发症、心理状态及睡眠质量的影响。方法:选取2019年7月至2022年9月福建医科大学附属第二医院收治的前列腺增生患者101例为研究对象,按照随机数字表法分为对照组(n=50)和观察组(n=51),对照组给予常规护理干预,观察组给予亲情护理服务干预。采用抑郁自评量表(SDS)、焦虑自评量表(SAS)比较2组患者干预前后焦虑、抑郁的改善情况,采用匹兹堡睡眠质量指数(PSQI)比较2组患者干预前后睡眠质量的变化,比较2组患者术后康复观察指标的变化,并比较2组患者并发症发生率。结果:干预后,观察组排气、膀胱冲洗、膀胱痉挛、留置尿管时间均短于对照组,差异均有统计学意义(均P<0.05);干预后,2组SDS评分、SAS评分、PSQI评分均下降,且观察组显著低于对照组,差异均有统计学意义(均P<0.05)。结论:对前列腺增生患者围手术期实行亲情护理服务干预,可缩短患者康复时间、改善心理状况、提高睡眠质量、减少并发症发生,具有显著的临床应用价值,值得临床推广应用。 展开更多
关键词 亲情护理服务 前列腺增生 围手术期 并发症 心理状态 睡眠质量
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位移电流测试方法的改进及应用 被引量:1
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作者 纪文宇 张汉壮 《物理与工程》 2024年第1期30-34,66,共6页
自从麦克斯韦第一次提出位移电流这一概念之后,其在薄膜表征中便得到广泛的应用。然而,在课堂教学中,极少涉及位移电流的测试原理及相关应用讲解,更缺少对其实际应用的介绍。本文从位移电流的测试原理出发,联系实际应用,提出了基于周期... 自从麦克斯韦第一次提出位移电流这一概念之后,其在薄膜表征中便得到广泛的应用。然而,在课堂教学中,极少涉及位移电流的测试原理及相关应用讲解,更缺少对其实际应用的介绍。本文从位移电流的测试原理出发,联系实际应用,提出了基于周期性阶跃电压驱动的电流测量(CPSIV)的新方法。这将有效地加深学生对于位移电流物理本质的深入理解。同时,我们以量子点发光二极管(QLED)为平台,对这一新的测试方案进行了实验验证。针对其中空穴传输层薄膜的缺陷特性及其对器件性能的影响进行了表征,揭示了器件的发光开启机制,证实了我们方案的可靠性。 展开更多
关键词 麦克斯韦方程 位移电流 周期性阶跃电压 长寿命缺陷态 量子点发光二极管
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The Effect of State-Dependent Control for an SIRS Epidemic Model with Varying Total Population
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作者 Fuwei Zhang Linfei Nie 《Journal of Applied Mathematics and Physics》 2016年第10期1889-1898,共10页
Based on the mechanism of prevention and control of infectious disease, we propose, in this paper, an SIRS epidemic model with varying total population size and state-dependent control, where the fraction of susceptib... Based on the mechanism of prevention and control of infectious disease, we propose, in this paper, an SIRS epidemic model with varying total population size and state-dependent control, where the fraction of susceptible individuals in population is as the detection threshold value. By the Poincaré map, theory of differential inequalities and differential equation geometry, the existence and orbital stability of the disease-free periodic solution are discussed. Theoretical results show that by state-dependent pulse vaccination we can make the proportion of infected individuals tend to zero, and control the transmission of disease in population. 展开更多
关键词 SIRS Epidemic Model Varying Total Population state-Dependent Pulse Control periodic Solution Orbital Stability
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