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Key Problems of Cold Power Spinning of Ti-15-3 Alloy 被引量:1
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作者 Debin SHAN Yan LU and Ping LI School of Materials Science and Engineering, Harbin institute of Thchnology, Harbin 150001, China Yi XU Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110015, China 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2001年第1期125-126,共2页
The key problems of cold power spinning of Ti-15-3 alloy are studied. Reasonable billet preparation methods are presented to improve crystal structure and avoid crack of billet. Influences of original wall thickness,... The key problems of cold power spinning of Ti-15-3 alloy are studied. Reasonable billet preparation methods are presented to improve crystal structure and avoid crack of billet. Influences of original wall thickness, reduction rate and feed rate on expanding in diameter are analyzed and some methods to prevent expanding in diameter are given. 展开更多
关键词 TI key Problems of Cold Power Spinning of Ti-15-3 Alloy
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Effect of Surface Roughness in Micro-nano Scale on Slotted Waveguide Arrays in Ku-band
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作者 Na LI Peng LI Liwei SONG 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第3期595-603,共9页
Modeling of the roughness in micro-nano scale and its influence have not been fully investigated, however the roughness will cause amplitude and phase errors of the radiating slot, and decrease the precision and effic... Modeling of the roughness in micro-nano scale and its influence have not been fully investigated, however the roughness will cause amplitude and phase errors of the radiating slot, and decrease the precision and efficiency of the SWA in Ku-band. Firstly, the roughness is simulated using the electromechanical coupled(EC) model. The relationship between roughness and the antenna's radiation properties is obtained. For verification, an antenna proto- type is manufactured and tested, and the simulation method is introduced. According to the prototype, a contrasting experiment dealing with the flatness of the radiating plane is conducted to test the simulation method. The advantage of the EC model is validated by comparisons of the EC model and two classical roughness models (sine wave and fractal function), which shows that the EC model gives a more accurate description model for roughness, the maxi- mum error is 13%. The existence of roughness strongly broadens the beamwidth and raises the side-lobe level of SWA, which is 1.2 times greater than the ideal antenna. In addition, effect of the EC model's evaluation indices is investigated, the most affected scale of the roughness is found, which is 1/10 of the working wavelength. The proposed research provides the instruction for antenna designing and manufacturing. 展开更多
关键词 slotted waveguide arrays - Roughness model Micro/nano-scale Amplitude and phase errors Radiationcharacteristics
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Stereoselective Synthesis of 2-(4-Hydroxyphenyl)-3-hydroxymethyl-1,4-benzodioxane-6-aldehyde—The Key Intermediate of Sinaiticin
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作者 Xue Gong SHE Wen Xin GU +1 位作者 Hua WANG Xin Fu PAN(Department of Chemistry,National Laboratory of Applied Oerganic Chemistry,Lanzhou University,Lanzhou 730000) 《Chinese Chemical Letters》 SCIE CAS CSCD 1999年第2期107-108,共2页
2-(4-Hydroxyphenyl)-3-hydroxymethyl-1,4-benzodioxane-6-aldehyde 8,the key intermediate of sinaiticin 10,was synthesized in 6 step from caffeic acid 4 and 4- hydroxybenzsaldehyde 1.the coupling reaction is the key step.
关键词 2-(4-Hydroxyphenyl)-3-hydroxymethyl-1 4-benzodioxane-6-aldehyde key intermediate sinaiticin SYNTHESIS
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KEY WORDS INDEX, RICE SCIENCE, VOL. 13, NO. 1-4, 2006
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《Rice science》 SCIE 2006年第4期I0005-I0006,共2页
关键词 VOL key WORDS INDEX RICE SCIENCE VOL.13 NO.1-4 2006 NO
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KEY WORDS INDEX, RICE SCIENCE, VOL. 14, NOS. 1-4, 2007
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《Rice science》 SCIE 2007年第4期I0005-I0006,共2页
关键词 VOL key WORDS INDEX RICE SCIENCE VOL.14 NOS.1-4 2007 gene NOS
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KEY WORDS INDEX, RICE SCIENCE, VOL. 16, NOS. 1-4, 2009
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《Rice science》 SCIE 2009年第4期I0005-I0006,共2页
关键词 gene NOS key WORDS INDEX RICE SCIENCE VOL.16 NOS.1-4 2009 VOL
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KEY WORDS INDEX, 《RICE SCIENCE》, VOL. 12, NO. 1-4, 2005
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《Rice science》 SCIE 2005年第4期I0007-I0009,共3页
关键词 VOL key WORDS INDEX RICE SCIENCE VOL.12 NO.1-4 2005 NO
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基于USB Key的安全增强密钥生成方案
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作者 赵波 李二辉 +1 位作者 马骏 黄宇晴 《计算机工程与应用》 CSCD 北大核心 2018年第10期135-142,共8页
针对目前嵌入式系统环境下密钥存储安全性不足的问题,提出了一种安全增强密钥(Security-Enhanced Key,SEK)的生成方案。该方案在不改变现有嵌入式系统(Embedded System,ES)架构的前提下,分别利用ES的唯一硬件特征值和USB Key(UK)产生的... 针对目前嵌入式系统环境下密钥存储安全性不足的问题,提出了一种安全增强密钥(Security-Enhanced Key,SEK)的生成方案。该方案在不改变现有嵌入式系统(Embedded System,ES)架构的前提下,分别利用ES的唯一硬件特征值和USB Key(UK)产生的随机数生成各自的密钥种子,之后ES和UK利用密钥种子进行迪菲-赫尔曼协商(Diffie-Hellman Key Exchange,DHKE)生成SEK。SEK仅在需要时生成,使用后即销毁,不需要在嵌入式设备上存储,从根本上提高了密钥的安全性,并在一定程度上解决了嵌入式系统密钥泄漏的安全问题。方案原型的实现和安全性评估表明,在嵌入式系统中加入该方案之后,密钥的安全性得到明显增强,能够抵抗针对嵌入式系统密钥的多种攻击,且增加的额外开销不会对系统性能造成显著影响。 展开更多
关键词 安全增强密钥 嵌入式系统 迪菲-赫尔曼协议 USB key 密钥存储
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TOPO-Ⅱ和GST-π双染色法在非小细胞肺癌研究中的应用
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作者 孙勤暖 王立红 +2 位作者 孙丽华 贺岚 顾岩 《中国肿瘤临床与康复》 2006年第3期207-208,共2页
关键词 非小细胞肺癌(NSCLC) TOPO- GST-Π 双染色法 谷胱甘肽S转移酶-Π DNA拓扑异构酶 抗体检测 分布情况 抗原 key
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硅-有机复合集成电光调制器的优化与制备 被引量:3
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作者 邹艳慧 王艺蒙 +10 位作者 张小雪 武震林 陈卓 薄淑晖 刘若男 李志华 王迪 谭庆贵 谷一英 赵明山 韩秀友 《光学精密工程》 EI CAS CSCD 北大核心 2020年第10期2138-2150,共13页
硅-有机复合光子集成技术充分发挥了硅光的大规模集成优势和有机聚合物材料的高电光系数优势,在高性能集成微波光子系统中极具应用潜力。本文对硅-有机复合集成电光调制器结构进行了较为全面地优化设计和初步制备研究。电光有机聚合物... 硅-有机复合光子集成技术充分发挥了硅光的大规模集成优势和有机聚合物材料的高电光系数优势,在高性能集成微波光子系统中极具应用潜力。本文对硅-有机复合集成电光调制器结构进行了较为全面地优化设计和初步制备研究。电光有机聚合物填充在硅Slot波导的狭缝中,优化Slot波导结构得到光场限制因子为0.32,使得光波场与射频电场高度重合,提高了电光调制效率。采用锥型波导模式转换结构实现Strip-to-Slot的低损耗耦合,耦合效率为99.55%。重点分析了电极长度、宽度等参数对调制器频率响应的影响,优化得到3 dB带宽为77 GHz,半波电压-长度积为0.045 V·cm。根据仿真结果设计了用于制备调制器的MASK。实验制备了Slot波导并进行了聚合物的填充实验研究,获得了良好的结果。 展开更多
关键词 电光调制器 -有机复合集成 slot波导 Strip-to-slot模式转换器 半波电压-长度积
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USB Key身份认证技术 被引量:7
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作者 王可一 《中国高新技术企业》 2007年第10期101-101,104,共2页
网络应用的安全问题十分重要,本文着重介绍了USB Key身份认证技术的特点、应用方式及基本原理。
关键词 USB key 冲击-响应的双因子认证 数字证书的认证
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Vitamin A supplement: a key strategy to prevent vitamin A deficiency among young children in Afghanistan
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作者 Ahmad Mujtaba Barekzai Abdullah Sahar Naseer Ahmad Shinwari 《Food Therapy and Health Care》 2022年第2期4-9,共6页
Background:Vitamin A deficiency is the main problem of public health worldwide demonstrated that 190 million population of preschool children and 122 countries(in Africa and South-East Asia)have vitamin A deficiency,a... Background:Vitamin A deficiency is the main problem of public health worldwide demonstrated that 190 million population of preschool children and 122 countries(in Africa and South-East Asia)have vitamin A deficiency,according to recent estimated research.In Afghanistan,vitamin A supplementation is a key strategy to prevent vitamin A deficiency among young children.Children receive vitamin A supplements as part of National Immunization Days(NID)campaigns.Methods:In this case study,the data was collected from June 15/2015 to February 23/2016,and the final report of the Afghanistan Demographic Health Survey(AfDHS)2015 was released on February 15/2017.All 27,209 children aged 6-59 months who are living with their mothers were included in this study.Who consumed foods rich in vitamin A was not included in this study.Results:The percentages who were given vitamin A supplements in the last 6 months among all children 6-59 months aged.A total of 1,572 children aged among 6-8 months were given vitamin A supplements 670(42.6%)children and comparison with the total community of the study(27,209)children(2.46%).A total of 1,148 children aged among 9-11 months were given vitamin A supplements to 465(40.5%)children and comparison with the total community of the study(27,209)children(1.70%).Conclusion:After following up on more studies,we found that vitamin A deficiency is a public problem,thus it is better to use wheat flour fortification,vitamin A capsule(VAC)supplementation,nutrition education,source of vitamin A,and training of primary healthcare workers on the clinical to prevent and treat the vitamin A deficiency among children.Therefore,we aimed to determine the given vitamin A supplementation among children aged 6-59 months in 33 provinces in Afghanistan,in 2015. 展开更多
关键词 vitamin A deficiency SUPPLEMENT children age 6-59 months key strategy
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科技期刊“关键词”编写格式规范建议 被引量:1
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作者 谢文亮 冯婷 《肇庆学院学报》 2023年第2期124-128,共5页
科技期刊中“关键词”一词有两种不同表达:Key words和Keywords,虽然编写形式不统一,没有造成太多文本分析的歧义,但给期刊规范、文献检索和作者写作带来不便,必须对其进行统一规范根据已有的公开的文献.,分析了Keywords和Keywords在英... 科技期刊中“关键词”一词有两种不同表达:Key words和Keywords,虽然编写形式不统一,没有造成太多文本分析的歧义,但给期刊规范、文献检索和作者写作带来不便,必须对其进行统一规范根据已有的公开的文献.,分析了Keywords和Keywords在英文中的定义、功能以及应用,对Keywords和Keywords的发展历史进行溯源后发现,Key word逐渐被Keyword所替代,并且从1995年后出版的字典中,再也没有出现过Key word的词条,其替代原因是科技论文发表数量剧增、科技论文交流的需要以及网络信息检索的兴起,使得Keyword成为信息检索和科技论文“关键词”的代号结合计算机信息检索和科技期刊中关键词的作用,对比结合GB/T7713-1987中对“关键词”的定义,提出使用Keywords作为科技期刊“关键词”一词的原因. 展开更多
关键词 科技期刊 关键词 信息检索 key words keyWORDS GB/T 7713-1987
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基于SOI的SOH电光调制器设计
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作者 齐影 安俊明 +2 位作者 王玥 张家顺 王亮亮 《半导体光电》 CAS 北大核心 2016年第1期7-12,共6页
设计了一种基于绝缘层上硅(SOI)的推挽式硅-有机物混合(SOH)马赫-曾德干涉型(MZI)电光调制器。利用薄膜模式匹配法对槽波导(slot)的光场分布进行了仿真分析,优化后得到了限制因子为0.32的slot波导结构。采用推挽式马赫-曾德干涉仪结构,... 设计了一种基于绝缘层上硅(SOI)的推挽式硅-有机物混合(SOH)马赫-曾德干涉型(MZI)电光调制器。利用薄膜模式匹配法对槽波导(slot)的光场分布进行了仿真分析,优化后得到了限制因子为0.32的slot波导结构。采用推挽式马赫-曾德干涉仪结构,并在相移臂嵌入LX M1非线性有机材料,得到半波电压-长度积V_π·L为0.885V·mm、电学响应带宽f_(RC)可达123.2GHz、开关速度为8.11ps的SOH调制器结构。利用基于本征有限元法求解麦克斯韦方程,对共平面波导电极系统进行了计算仿真,获得了特性阻抗接近50Ω、高频速率匹配的电极结构。 展开更多
关键词 SOH 马赫-曾德干涉仪 电光调制器 slot波导 共平面波导行波电极
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浅析车与车通信网络时间同步
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作者 吴承治 《现代传输》 2014年第3期12-19,共8页
本文首先描述了车联网中车与车通信网络的概念及架构,在分析了TD-SCDMA网络时间同步技术的基础上,重点讨论了基于TD-SCDMA的车载Ad Hoc网络时间同步技术及相应的同步算法,包括基于GPS/北斗的时间同步和基于分布的时间同步方案。
关键词 车与车通信(Inter—Vehicle Communication IVC) 车载Ad Hoc网络(VANET) 时分-同步码分多址接入(TD—SCDMA) 时隙同步(slot Synchronjzafjon).
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Variation of sea ice extent in different regions of the Arctic Ocean 被引量:4
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作者 CHEN Ping ZHAO Jinping 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2017年第8期9-19,共11页
Sea ice in the Arctic has been reducing rapidly in the past half century due to global warming. This study analyzes the variations of sea ice extent in the entire Arctic Ocean and its sub regions. The results indicate... Sea ice in the Arctic has been reducing rapidly in the past half century due to global warming. This study analyzes the variations of sea ice extent in the entire Arctic Ocean and its sub regions. The results indicate that sea ice extent reduction during 1979-2013 is most significant in summer, following by that in autumn, winter and spring. In years with rich sea ice, sea ice extent anomaly with seasonal cycle removed changes with a period of 4-6 years. The year of 2003-2006 is the ice-rich period with diverse regional difference in this century. In years with poor sea ice, sea ice margin retreats further north in the Arctic. Sea ice in the Fram Strait changes in an opposite way to that in the entire Arctic. Sea ice coverage index in melting-freezing period is an critical indicator for sea ice changes, which shows an coincident change in the Arctic and sub regions. Since 2002, Region C2 in north of the Pacific sector contributes most to sea ice changes in the central Aarctic, followed by C1 and C3. Sea ice changes in different regions show three relationships. The correlation coefficient between sea ice coverage index of the Chukchi Sea and that of the East Siberian Sea is high, suggesting good consistency of ice variation. In the Atlantic sector, sea ice changes are coincided with each other between the Kara Sea and the Barents Sea as a result of warm inflow into the Kara Sea from the Barents Sea. Sea ice changes in the central Arctic are affected by surrounding seas. 展开更多
关键词 key words: Arctic sea ice extent period of 4-6 years sea ice margin sea ice coverage indices
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Instructions to authors
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《World Journal of Gastroenterology》 SCIE CAS CSCD 2005年第28期i0003-i0004,共2页
An informative, structured abstract of no more than 250 words should accompany each manuscript. Abstracts for original contributions should be structured into the following sections: AIM: Only the purpose should be ... An informative, structured abstract of no more than 250 words should accompany each manuscript. Abstracts for original contributions should be structured into the following sections: AIM: Only the purpose should be included. METHODS: The materials, techniques, instruments and equipments, and the experimental procedures should be included. RESULTS: The observatory and experimental results, including data, effects, outcome, etc. should be included. Authors should present P value where necessary, and the significant data should accompany. CONCLUSION: Accurate view and the value of the results should be included. The format of structured abstracts is at: http://www.wjgnet.com/wjg/help/11 .doc 展开更多
关键词 Please list 3-10 key words that could reflect content of the study.
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Information for Authors
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《Journal of Beijing Institute of Technology》 EI CAS 2011年第1期F0003-F0003,共1页
An abstract not more than results and conclusion, should stracting journals, so it should 150 words, adequate as an index and summary, and including the aim, methods, appear at the beginning of the paper. The abstract... An abstract not more than results and conclusion, should stracting journals, so it should 150 words, adequate as an index and summary, and including the aim, methods, appear at the beginning of the paper. The abstract may be used in toto by the ab be self contained. 展开更多
关键词 key words should be 3-8 pieces of words or phrases that will assist readers and indexers in cross-indexing thisstudy.
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Profit loss indicator:a novel maintenance indicator applied for integrated planning 被引量:1
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作者 Harald RФdseth Terje Skarlo Per SchjФlberg 《Advances in Manufacturing》 SCIE CAS CSCD 2015年第2期139-150,共12页
In production environment today, "silo think- ing" is a challenge where controlling an asset associated with several disciplines and departments can lead to a sub- optimal result. This requires a more integrated app... In production environment today, "silo think- ing" is a challenge where controlling an asset associated with several disciplines and departments can lead to a sub- optimal result. This requires a more integrated approach with an integrated planning (IPL) framework. In this framework novel maintenance key performance indicators (KPIs) are needed. The purpose of this article is to develop the novel maintenance KPI profit loss indicator (PLI). This indicator is based on measuring both on the "hidden fac- tory" and waste in production, presenting it as a financial measure. The notion "hidden factory" is used as a meta- phor for measuring the time losses in industry through the maintenance KPI overall equipment effectiveness (OEE). This indicator divides the time losses into availability losses, performance losses and quality losses. In addition, a financial measure for waste based on literature from Toyota production system (TPS) and waste treatment and disposal is also included in PLI. Through a case study in the saw mill industry PLI is demonstrated and evaluated. It is expected that this indicator will be demonstrated in several industry branches in the future. 展开更多
关键词 Integrated planning (IPL) - Maintenanceperformance key performance indicator (KPI) Hidden factory WASTE Asset management
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