检索结果-南通市图书馆

Electronic structures and properties of Ti, Zr and Hf metals

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University of Technology 2001年第2期8卷 83-88页

作者： XIE you qing,peng Kun,YANG Xin xin (Department of Materials Science and Engineering, Central South University, Changsha 410083, China) 1. Department of Materials Science and Engineering Central South University 410083 Changsha China

The electronic structures of pure Ti, Zr and Hf metals with hcp structure were determined by one atom (OA) theory. According to the electronic structures of these metals,their potential curves, cohesive energies, lattice constants, elasticities and the temperature dependence of linear thermal expansion coefficients were calculated. The electronic structures and characteristic properties of these metals with bcc and fcc structures and liquids were also studied. The results show that the electronic structures of Ti, Zr and Hf metals are respectively [Ar](3d n) 0.481 0 (3d c) 2.085 7 (4s c) 1.000 0 (4s f) 0.433 3 , [Kr](4d n) 0.396 8 (4d c) 2.142 8 (5s c) 1.262 0 (5s f) 0.198 4 , [Xe](5d n) 0.368 0 (5d c) 2.041 4 (6s c) 1.406 6 (6s f) 0.184 0 . It is explained why the pure Ti, Zr and Hf metals with hcp and bcc structures can exist naturally, while those with fcc structure can not.

关键词： electronic structure Ti Zr Hf lattice constant cohesive energy crystal structure

Structures and Properties of Sc and Y Metals

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2000年第3期12卷 136-139页

作者： peng Kun,XIE you qing,peng Hao,XU Ying hong (Department of Materials Science and Engineering, Central South University, Changsha 410083, China) 1. Department of Materials Science and Engineering Central South University 410083 Changsha China

The electronic structures of pure Sc and Y metals with hcp structure have been determined by one atom (OA) theory, which are [Ar](3d c) 1.331 5 (4s c) 0.905 0 (4s f) 0.763 5 and [Kr](4d c) 1.293 0 (5s c) 0.947 0 (5s f) 0.760 0 . According to their electronic structure, their potential curves, cohesive energies, lattice constants, elasticity and the temperature dependence of linear thermal expansion coefficients have been calculated. The electronic structures and characteristic properties of these metals with bcc structures and primary liquids have also been studied, which has supplied the structural parameters and property parameters of Sc and Y with different crystal structures and also supplied a series of complete data for the theoretical design of Sc and Y based materials.

关键词： scandium yttrium electronic structure cohesive energy crystal structure

Efficacies of Different Methods of Teaching Transcultural Nursing Practice in China

在线全文

学校读者我要写书评

暂无评论

Chinese Nursing Research 2014年第1期1卷 14-24页

作者： Lenny Chiang-Hanisko you-qing peng Christine E.Lynn College of Nursing Florida Atlantic Universjity Department of Nursing East Hospital of School of MedicineTongji University

Purpose： This study assessed the effectiveness of three teaching methods for developing cultural competency based upon Leininger＇s theoretical framework with nursing students in China： case studies, traditional didactic learning, and self-directed learning. These methods were used in tran- scultural nursing teaching practices to identify the method that resulted in the greatest improve- ments in the nursing student＇s understanding and clinical application of transcultural nursing. Methods： The Transcultural Nursing Questionnaire（TNQ） was used for pre-and post-test comparisons of all participants in four areas of cultural knowledge and the Evaluation of Transcultural Nursing Competency（ETNC） was applied via role-play to evaluate the cultural competency of 120 of the 305 participants from three general hospitals in the PuDong New District, Shanghai, China. Individual transcultural nursing courses that focused on case study, traditional didactic or self-di- rected methods persisted for four months in three hospitals. Results： Statistical analyses of the cognitive scores of the participants in the transcultural nursing courses revealed a significant difference（P〈0.01） between scores collected before and after the teaching with the three methods. Comparisons of the three hospitals revealed that the scores for transcultural nursing cognition and simulating service assessment were significantly different（P〈0.01） for the case study nursing students. The scores of the students who were taught with the traditional didactic and self-directed methods were not significantly different across the three hospitals（P〉0.05）. Conclusion： The results revealed that the case study, traditional didactic and self-directed method effectively improved the transcultural nursing cognitive levels of the nursing students. The case study method appeared to be the most effective approach based upon the TNQ pre-and post-tests and the ETNC cultural competency scores.

关键词： transcultural nursing case study traditional didactic teaching self-directed learning cultural competency China

Research on Alloying Design and Process Control for X100 Hot-Rolled Strips

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2011年第S1期18卷 675-680页

作者： JIA Shu-jun 1,LIU qing-you 1,peng Ling-li 1,QU peng 2 (1.China Iron and Steel Research Institute Group,Beijing 100081,China 2.Benxi Steel Group Corporation,Benxi 100083,Liaoning,China) China Iron & Steel Res Inst Grp Beijing 100081 Peoples R China Benxi Steel Grp Corp Benxi 100083 Liaoning Peoples R China

The influence of alloying design,controlled rolling technology and cooling system of X100 hot-rolled strips on microstructure and micro-hardness has been discussed in detail in this *** results show that optimal chemical composition range of X100 hot-rolled strips is obtained on the basis of X80 by increasing contents of C,Mn,Ni and Mo of *** granular bainite microstructure could be refined and the volume fraction and size of M-A islands could be controlled in a reasonable range by reasonably regulating cooling rate and coiling temperature of X100 pipeline steel,which ensure high strength and toughness of X100 pipeline steel.

关键词： alloying design deformation cooling rate final cooling temperature granular bainite

新质生产力赋能乡村数字化治理:运作机理、实践悖论与风险规避

在线全文

学校读者我要写书评

暂无评论

河北学刊 2025年第1期45卷 202-209页

作者：王鹏王向清湘潭大学湘潭大学马克思主义学院

作为新时代乡村治理现代化的发展目标,乡村数字化治理是推进乡村振兴的关键环节。新质生产力赋能乡村数字化治理具有多重实施路径,通过“人的现代化”“物的现代化”“治理的现代化”与“技术的现代化”,立体构成赋能进程的运作机理。... 详细信息

作为新时代乡村治理现代化的发展目标,乡村数字化治理是推进乡村振兴的关键环节。新质生产力赋能乡村数字化治理具有多重实施路径,通过“人的现代化”“物的现代化”“治理的现代化”与“技术的现代化”,立体构成赋能进程的运作机理。在赋能过程中所呈现的实践悖论具体表征为乡村数字化治理需求显现脱节情形、乡村建设基础设施伴生缺失风险、乡村数字化治理专业人才短缺、乡村数字化治理泛起内源动力不足、城乡之间数字鸿沟愈加凸显等客观现象,从而阻滞了乡村数字化治理的实践进程。为消解新质生产力赋能乡村数字化治理的实践偏差,应实现治理内容的有效融合与治理需求的有效对接,助推数字设施的广泛普及与乡村资源的充分开发,推动专业人才的重点培育与治理主体数字素养的全面提升,促进内源动力的有效激活与公共合作精神的最终形成,提升新质技术的发展水平与赋能发展的制度保障。

关键词：新质生产力乡村数字化治理运作机理实践悖论风险规避

在线全文

学校读者我要写书评

暂无评论

一种新的数字图像灰度直方图及其应用研究

系统仿真学报 2002年第12期14卷 1655-1658页

作者：张佑生彭青松汪荣贵合肥工业大学计算机与信息学院合肥230009

一般的描述数字图像的直方图不能反映图像中的局部特征和对象属性.本文提出一种新的灰度直方图, 其特点是具有描述图像局部特征能力.文章给出了它的定义, 并对其中的特别区域及其与图像中字幕的映射关系作了分析。在此基础上, 我们进一... 详细信息

一般的描述数字图像的直方图不能反映图像中的局部特征和对象属性.本文提出一种新的灰度直方图, 其特点是具有描述图像局部特征能力.文章给出了它的定义, 并对其中的特别区域及其与图像中字幕的映射关系作了分析。在此基础上, 我们进一步研究了这种直方图在字幕检测与定位中的应用, 并为此目的提出了一种算法。计算实验结果表明, 该算法快速有效。

关键词：数字图像灰度直方图视频图像图像识别多媒体

Alport syndrome combined with lupus nephritis in a Chinese family:A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2021年第18期9卷 4721-4727页

作者： Hui-Fang Liu qing Li you-Qun peng Department of Nephrology Traditional Chinese Medicine Hospital of Jiulongpo DistrictChongqing 400050China

BACKGROUND Alport syndrome(ATS)is a rare hereditary disease caused by mutations in genes such as COL4A3,COL4A4,and *** involves a spectrum of phenotypes ranging from isolated hematuria that is nonprogressive to progressive renal disease with extrarenal *** ATS can be combined with other diseases or syndromes,ATS combined with lupus nephritis has not been reported *** SUMMARY A Chinese family with ATS was recruited for the current *** characteristics(including findings from renal biopsy)of ATS patients were collected from medical records,and potential causative genes were explored by whole-exome sequencing.A heterozygous substitution in intron 22 of COL4A3(NM_000091 c.2657-1G>A)was found in the patients,which was further confirmed by quantitative polymerase chain *** Heterozygous substitution of a COL4A3 gene splice site was identified by wholeexome sequencing,revealing the molecular pathogenic basis of this *** general,identification of pathogenic genes can help to fully understand the molecular mechanism of disease and facilitate precise treatment.

关键词： Alport syndrome Lupus nephritis COL4A3 Whole-exome sequencing Splice site Case report

Achieving and maintaining biological nitrogen removal via nitrite under normal conditions

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

Journal of Environmental Sciences 2005年第5期17卷 794-797页

作者： CUI you-wei peng Yong-zhen GAN Xiang-qing YE Liu WANG Ya-yi College of Environmental and Energy Engineering Beijing University of Technology Beijing 100022 China Department of Chemistry Fuling Normal University Chongqing 408003 China School of Civil Engineering and Architecture Zhejiang University of Technology Hangzhou 310014 China

The principal aim of this paper is to develop an approach to realize stable biological nitrogen removal via nitrite under normal conditions. Validation of the new method was established on laboratory-scale experiments applying the sequencing batch reactor（SBR） activated sludge process to domestic wastewater with low C/N ratio. The addition of sodium chloride（NaCI） to influent was established to achieve nitrite build-up. The high nitrite accumulation, depending on the salinity in influent and the application duration of salt, was obtained in SBRs treating saline wastewater. The maintenance results indicated that the real-time SBRs can maintain stable nitrite accumulation, but conversion from shorter nitrification-denitrification to full nitrification-denitrification was observed after some operation cycles in the other SBR with fixed-time control. The presented method is valuable to offer a solution to realize and to maintain nitrogen removal via nitrite under normal conditions.

关键词： nitrite accumulation salt selective inhibition real-time control of nitrification biological nitrogen removal via nitrite nitrite-oxidizers ammonium-oxidizers

在线全文

学校读者我要写书评

暂无评论

糖尿病早期视网膜神经变性研究新进展

国际眼科杂志 2025年第1期25卷 76-81页

作者：魏凡彭立谢青中南大学湘雅医学院附属海口医院眼科海南省海口市570208

糖尿病视网膜病变(DR)是由慢性高血糖引起的晚期微神经血管并发症,可导致血-视网膜屏障受损和视网膜功能障碍。近年来研究发现,糖尿病视网膜神经变性(DN)可能是糖尿病的视网膜改变最早事件之一,主要表现包括:新诊断糖尿病患者的视网膜... 详细信息

糖尿病视网膜病变(DR)是由慢性高血糖引起的晚期微神经血管并发症,可导致血-视网膜屏障受损和视网膜功能障碍。近年来研究发现,糖尿病视网膜神经变性(DN)可能是糖尿病的视网膜改变最早事件之一,主要表现包括:新诊断糖尿病患者的视网膜电图反应缺陷;发病初期,小胶质细胞和Müller细胞在几周内自我激活并激活相关蛋白;神经递质(如DOPA/GABA)活性降低,损害神经节信号传递;早期线粒体功能障碍,如Drp1-Fis1持续裂变及mtDNA甲基化和碱基错配之间的潜在串扰等。探讨糖尿病早期视网膜神经变性的分子基础对于理解DN的发病机制及早期治疗至关重要。文章总结糖尿病早期视网膜感光功能及神经胶质细胞、神经递质、线粒体和其他因子的病理变化及机制,旨在为研究DN早期机制及靶向治疗提供理论依据。

关键词：糖尿病视网膜病变糖尿病视网膜神经变性视网膜电图线粒体自噬神经胶质细胞多巴胺