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荒漠型杜氏利什曼原虫虫株在体内外的致病力及保存方法研究
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作者 廖力夫 罗芸 +1 位作者 史深 徐艺玫 《实验动物与比较医学》 CAS 2023年第6期619-625,共7页
目的通过动物攻毒实验观察荒漠型杜氏利什曼原虫虫株在动物体内外的致病力,探索保持该虫株致病力的保存方法。方法将从rK39抗体阳性灰仓鼠脾脏中分离获得的荒漠型杜氏利什曼原虫虫株分别在体外培养基中传代培养至7 d、30 d、36 d、44 d... 目的通过动物攻毒实验观察荒漠型杜氏利什曼原虫虫株在动物体内外的致病力,探索保持该虫株致病力的保存方法。方法将从rK39抗体阳性灰仓鼠脾脏中分离获得的荒漠型杜氏利什曼原虫虫株分别在体外培养基中传代培养至7 d、30 d、36 d、44 d、60 d、90 d和150 d后,按2.6×10^(5)条/只剂量腹腔接种至草原兔尾鼠,接种后60 d计算动物的脾脏系数、虫株感染率和抗体阳性率。进一步将荒漠型杜氏利什曼原虫虫株分别接种灰仓鼠和草原兔尾鼠进行传代保种,比较两种动物感染该虫株后的存活时间和致病力变化。结果体外培养7~150 d的荒漠型杜氏利什曼原虫虫株接种后,草原兔尾鼠的脾脏系数由7 d的1.0%上升至30 d的2.2%,达到正常脾脏系数(0.15%)的10倍以上,而60 d的脾脏系数虽有下降,但仍然达正常值的3倍;虫株感染率和抗体阳性率由7 d的80%逐步下降至60 d的0%;90 d时的各项观测指标与对照组相比无明显差异,均在正常值范围内。传代感染虫株后,草原兔尾鼠的存活时间为1~13个月,感染的半数个体于接种后4个月内死亡;而灰仓鼠的存活时间为5~31个月,感染的半数个体于接种后13.7个月内死亡;两种动物的平均死亡时间差异显著(t=0.0001,P<0.001),脾脏系数差异无统计学意义(t=0.990,P>0.05)。该虫株在两种动物体内的致病力一致,且在动物体内连续传代4年仍然具有致病力。结论荒漠型杜氏利什曼原虫虫株随体外培养时间延长,其致病力逐步降低,90 d时对草原兔尾鼠已无致病力,说明培养基传代培养方法不能保持该虫株对动物的致病力。动物体内传代接种才可以保持该虫株对动物的致病力。 展开更多
关键词 黑热病 荒漠型杜氏利什曼原虫 致病 维持 草原兔尾鼠 灰仓鼠
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课堂改进应协同三种力量 被引量:1
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作者 许大成 《江苏教育》 2021年第10期78-78,共1页
最近笔者看到一篇文章,题目是《CEO必须拥有的三种力量》,这三种力量一是管好过去的维持力,二是正视当下的颠覆力,三是开辟未来的创新力。文章指出,公司若想经久不衰,就必须使维持力、颠覆力和创造力保持恰当的平衡,而实现这一平衡则是... 最近笔者看到一篇文章,题目是《CEO必须拥有的三种力量》,这三种力量一是管好过去的维持力,二是正视当下的颠覆力,三是开辟未来的创新力。文章指出,公司若想经久不衰,就必须使维持力、颠覆力和创造力保持恰当的平衡,而实现这一平衡则是CEO的首要任务。由此笔者想到,每一位教师也是课堂中的CEO,应该在如火如荼的新课改热潮中,协同运用三种力量,打造指向核心素养的高效课堂。 展开更多
关键词 课堂改进 维持力 颠覆 创新
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课外补习、贫富差距的映像与代际变化 被引量:10
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作者 陈全功 《西北人口》 CSSCI 2009年第5期89-92,96,共5页
本文以武汉市L小学和M大学的调查为基础,说明课外补习与贫富差距之间的联系。各种形式和内容的课外补习既是城乡差距和贫富差距的具体映像,也是维持和推动社会贫富差距的重要力量,使得这一差距具有代际传递特征。在人们越来越关注学校... 本文以武汉市L小学和M大学的调查为基础,说明课外补习与贫富差距之间的联系。各种形式和内容的课外补习既是城乡差距和贫富差距的具体映像,也是维持和推动社会贫富差距的重要力量,使得这一差距具有代际传递特征。在人们越来越关注学校教育公平的今天,课外补习对贫富差距的形成与扩大的消极作用却被忽视;但它所起的维持和传递作用在将来会更大、更顽固。因此,政府要将课外补习限制在一定范围内,并改革正规学校教育系统及人才评估与选拔机制,尽可能地消减这一市场活动的负面作用。 展开更多
关键词 课外补习 贫富差距 映像 维持力 推动
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筋膜手法按摩配合内核心肌群训练联合脉管平滑肌电刺激对产后腹直肌分离的临床疗效分析
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作者 谢谨 卢嘉茵 黎婉仪 《实用妇科内分泌电子杂志》 2023年第26期10-14,共5页
目的探讨筋膜手法按摩配合内核心肌群训练联合脉管平滑肌电刺激对产后腹直肌分离的临床疗效。方法选取110例产后42d至1年内复查并确诊为腹直肌分离(≥2cm)的产妇患者为研究对象,根据治疗措施不同分为两组。单纯组52例采用单纯电刺激,联... 目的探讨筋膜手法按摩配合内核心肌群训练联合脉管平滑肌电刺激对产后腹直肌分离的临床疗效。方法选取110例产后42d至1年内复查并确诊为腹直肌分离(≥2cm)的产妇患者为研究对象,根据治疗措施不同分为两组。单纯组52例采用单纯电刺激,联合组58例采用筋膜手法按摩+内核心肌群训练+单纯电刺激,比较两组治疗前后腹围、腹直肌静息肌电位、腹直肌最大肌电位、腹直肌间距及腹直肌肌力维持时间。结果治疗后两组腹围(脐上5cm、脐部、脐下5cm)、腹直肌静息肌电位小于治疗前,腹直肌最大肌电位大于治疗前,但治疗后两组比较差异无统计学意义(P>0.05);治疗后两组腹直肌间距(脐上3cm、脐部、脐下3cm)小于治疗前,且联合组小于单纯组(P<0.05);两组治疗后腹直肌肌力维持时间长于治疗前,但两组比较差异无统计学意义(P>0.05)。结论针对产后腹直肌分离患者,采用筋膜手法按摩配合内核心肌群训练联合脉管平滑肌电刺激,既可缩小患者腹直肌间距和腹围,减小静息肌电位,还可以增加最大肌电位,延长肌力维持时间,可推广应用。 展开更多
关键词 筋膜手法按摩 核心肌群 平滑肌 腹直肌分离 静息肌电位 最大肌电位 维持时间
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加拿大安大略护士协会2013年第2版《营造并维持护理领导力》临床实践指南解读 被引量:2
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作者 赵源 郭海玲 +3 位作者 郝玉芳 田润溪 郑莉萍 王玲 《中华现代护理杂志》 2020年第34期4717-4723,共7页
本文对加拿大安大略注册护士协会(RNAO)2013年发表的第2版《营造并维持护理领导力》最佳临床实践指南的推荐意见进行解读和探索,分析指南条目在临床应用中的实践方法和可及性,以期为国内临床护理领导力的营造与维持提供依据。
关键词 实践指南 护理领导 《营造并维持护理领导 解读
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Pressure Buildup Analysis Using Type Curves for a Well in a Pressure-Maintained System
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作者 林加恩 杨慧珠 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第1期6-11,共6页
The development and application of a new solution is demonstrated for the type-curve analysis and in-terpretation of well test data from a multiwell reservoir system of both production and injection wells with two-pha... The development and application of a new solution is demonstrated for the type-curve analysis and in-terpretation of well test data from a multiwell reservoir system of both production and injection wells with two-phase flow. The buildup type curves or buildup behavior could be obtained through the solution by using su-perposition. But a new outer boundary condition for variable pressure boundary must be introduced to obtain the correct pressure buildup solutions by superposition. A technique is shown to determine the deviation time from the infinite-acting semilog radial flow stabilization in the derivatives of pressure, which is calculated with respect to and plotted vs. shut-in time. Field examples are given to illustrate the use of the proposed method for analyzing transient pressure data from a well located in a multi-well water-injection reservoir. An adaptive genetic algorithm-based method is used to match the pressure and pressure derivative data to estimate reservoir parameters. The validity and applicability of the proposed method are also demonstrated through the examples. 展开更多
关键词 multi-well reservoir pressure buildup two-phase flow type curve analysis
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Effect of Market Power in Electricity Markets
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作者 马歆 侯志俭 +1 位作者 蒋传文 刘涌 《Journal of Donghua University(English Edition)》 EI CAS 2003年第4期137-140,共4页
The main objective of this paper is to show an overview analysis of market power issues.Market power reflects the scarcity of power supply.It is the ability of a particular seller or group of sellers to maintain price... The main objective of this paper is to show an overview analysis of market power issues.Market power reflects the scarcity of power supply.It is the ability of a particular seller or group of sellers to maintain prices profitably above competitive levels for a significant period of time.Because the electric power system has its own characteristics that are different to other economic systems,both physical factors and economic factors of power system are key elements on this definition.We study some cases here,including different line limit levels,load levels and bid strategy through a market model based on OPF (optimal power flow) with a decommitment algorithm. 展开更多
关键词 Electricity market Market power analysis OPF market model
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Supervisory control of the hybrid off-highway vehicle for fuel economy improvement using predictive double Q-learning with backup models 被引量:1
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作者 SHUAI Bin LI Yan-fei +2 位作者 ZHOU Quan XU Hong-ming SHUAI Shi-jin 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第7期2266-2278,共13页
This paper studied a supervisory control system for a hybrid off-highway electric vehicle under the chargesustaining(CS)condition.A new predictive double Q-learning with backup models(PDQL)scheme is proposed to optimi... This paper studied a supervisory control system for a hybrid off-highway electric vehicle under the chargesustaining(CS)condition.A new predictive double Q-learning with backup models(PDQL)scheme is proposed to optimize the engine fuel in real-world driving and improve energy efficiency with a faster and more robust learning process.Unlike the existing“model-free”methods,which solely follow on-policy and off-policy to update knowledge bases(Q-tables),the PDQL is developed with the capability to merge both on-policy and off-policy learning by introducing a backup model(Q-table).Experimental evaluations are conducted based on software-in-the-loop(SiL)and hardware-in-the-loop(HiL)test platforms based on real-time modelling of the studied vehicle.Compared to the standard double Q-learning(SDQL),the PDQL only needs half of the learning iterations to achieve better energy efficiency than the SDQL at the end learning process.In the SiL under 35 rounds of learning,the results show that the PDQL can improve the vehicle energy efficiency by 1.75%higher than SDQL.By implementing the PDQL in HiL under four predefined real-world conditions,the PDQL can robustly save more than 5.03%energy than the SDQL scheme. 展开更多
关键词 supervisory charge-sustaining control hybrid electric vehicle reinforcement learning predictive double Q-learning
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Neural Networks for Condition Monitoring of Wind Turbines Gearbox
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作者 Roque Filipe Mesquita Brandao Jose Antonio Beleza Carvalho Fernando Pires Maciel Barbosa 《Journal of Energy and Power Engineering》 2012年第4期638-644,共7页
Wind energy is considered a hope in future as a clean and sustainable energy, as can be seen by the growing number of wind farms installed all over the world. With the huge proliferation of wind farms, as an alternati... Wind energy is considered a hope in future as a clean and sustainable energy, as can be seen by the growing number of wind farms installed all over the world. With the huge proliferation of wind farms, as an alternative to the traditional fossil power generation, the economic issues dictate the necessity of monitoring systems to optimize the availability and profits. The relatively high cost of operation and maintenance associated to wind power is a major issue. Wind turbines are most of the time located in remote areas or offshore and these factors increase the referred operation and maintenance costs. Good maintenance strategies are needed to increase the health management of wind turbines. The objective of this paper is to show the application of neural networks to analyze all the wind turbine information to identify possible future failures, based on previous information of the turbine. 展开更多
关键词 Condition monitoring maintenance neural networks wind energy.
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自然垄断的起因与属性分析 被引量:3
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作者 沈剑飞 张文泉 《管理世界》 CSSCI 北大核心 2001年第6期195-196,共2页
关键词 垄断 自然垄断 成本 形成因素 维持力 规模经济
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自然垄断理论演进综述 被引量:38
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作者 于立 肖兴志 《经济学动态》 CSSCI 北大核心 2000年第6期70-73,共4页
自然垄断理论是现代产业经济学(In-dustrial Economics)理论中发展较为迅速的一个组成部分。自然垄断理论的发展演进导致了20世纪70年代以来西方发达国家对许多过去被认为必须加以规制的产业部门都取消或放松了规制。在这一规制改革的背后,
关键词 规模经济 自然垄断 成本劣加性 维持力
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