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A New Northern Flank: Sweden and Finland in NATO
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作者 Magnus Christiansson 《International Relations and Diplomacy》 2023年第5期225-232,共8页
On June 282022 Sweden and Finland were invited to join NATO.During a symbolic ceremony at the NATO Madrid Summit,all the central actors gathered in front of the cameras,as if to replicate a“family photo”in mini form... On June 282022 Sweden and Finland were invited to join NATO.During a symbolic ceremony at the NATO Madrid Summit,all the central actors gathered in front of the cameras,as if to replicate a“family photo”in mini format:representatives from Sweden,Finland,and Turkey,as well as Secretary General Stoltenberg.The atmosphere was mixed:tense because of the dramatic backdrop of the Summit,relief because of the speedy process that had taken the process further.It was finally happening:Sweden and Finland would join the Atlantic Pact.But how did they get there?Over a few hectic months,two countries strongly associated with neutrality had moved their policies from emphasizing continuity to altering the very foundations of their security.Not only NATO critics were taken by surprise.Many NATO supporters were astonished by the rapid pace and the turnaround of the Swedish Social Democratic party.The relatively quick turnaround in Stockholm also meant that questions about the future and the consequences of NATO membership were postponed,not least because the Swedish election campaign put a lid on debate about strategic consequences:what journey awaits in the future and what strategic consequences does a future NATO membership have?This article discusses these questions in the belief that the temporal perspectives are connected:Sweden’s historical collaboration with NATO had significance for the country’s partner relationship,and in turn this influenced how Sweden became a member and what challenges the country faces together with its allies on a new northern flank in Europe. 展开更多
关键词 Sweden NATO Cold War ENLARGEMENT Northern flank
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Wettable-Flanks QFN汽车电子器件封装技术
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作者 奚啸晨 《中国集成电路》 2023年第6期81-85,共5页
Wettable-Flanks结构是一种替代传统QFN/DFN类封装形式的新结构工艺,其工艺产品本身具有一定性能优势,并且随着其技术应用的拓展,传统封装产品结构变得多样化。本文针对Wettable-Flanks产品的结构设计以及工艺设计发展方向进行了研究,... Wettable-Flanks结构是一种替代传统QFN/DFN类封装形式的新结构工艺,其工艺产品本身具有一定性能优势,并且随着其技术应用的拓展,传统封装产品结构变得多样化。本文针对Wettable-Flanks产品的结构设计以及工艺设计发展方向进行了研究,分析了Wettable-Flanks产品的性能优势。 展开更多
关键词 Wettable-flanks 汽车电子器件 自动视觉检查(AVI) 可靠性
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Isolating the Mutator Transposable Element Insertional Mutant Gene mio16 of Maize Using Double SelectedAmplification of Insertion Flanking Fragments (DSAIFF)
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作者 ZHONG Wen-juan ZHANGMei-dong +4 位作者 YANG Liu-qi WANG Ming-chun ZHENG Yong-lian YANG Wen-peng GAO You-jun 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2012年第10期1592-1600,共9页
Mutator transposable element (Mu) has been used as an effective tool to clone maize (Zea mays L.) genes. One opaque endosperm mutant (miol6) was identified in a pool of Mu inserted mutants. A modified method, te... Mutator transposable element (Mu) has been used as an effective tool to clone maize (Zea mays L.) genes. One opaque endosperm mutant (miol6) was identified in a pool of Mu inserted mutants. A modified method, termed the double selected amplification of insertion flanking fragments (DSAIFF), was employed to isolate the Mu flanking fragments (MFFs) of miol6. The target site duplications (TSDs) isolated from the Msp I and Mse I digested MFFs had a same 9-bp sequence and were confirmed to be the flanking sequence of one identically inserted gene. Co-segregation analysis suggested that the MFFs were associated with the mutant opaque endosperm, and miol6 was mapped in silico onto the physical position ranged from 229 965 021 to 229 965 409 bp of the maize chromosome 4.09 bin. The full-length cDNA of the wild-type gene was obtained by an RT-PCR primer-scanning technique, and Mio16 was found to putatively encode a homolog of the Arabidopsis MAP3K delta-1 protein kinase. RT-PCR result the mRNA expression of miol6 region anchored by primers Mu20 and af276 was not interrupted by Mu insertion. Further researches will be done to elucidate how the expression of miol6 is alternated by Mu insertion. 展开更多
关键词 maize (Zea mays L.) Mutator (Mu) transposable element Mu flanking fragments (MFFs) double selected amplification of insertion flanking fragments (DSAIFF) miol6
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石榴子石Fe^(3+)含量电子探针原位分析:Flank Method方法的实例应用 被引量:8
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作者 李小犁 陶仁彪 +2 位作者 李清云 朱建江 张立飞 《岩石学报》 SCIE EI CAS CSCD 北大核心 2019年第4期1058-1070,共13页
电子探针分析技术主要应用于对物质进行快速无损的定性、定量分析,是材料科学和地质学领域最基础和重要的研究手段。而利用电子探针对矿物中不同价态Fe的含量进行原位定量分析,更是具有非常重要的科学意义。近来发展起来的可进行Fe^(3+)... 电子探针分析技术主要应用于对物质进行快速无损的定性、定量分析,是材料科学和地质学领域最基础和重要的研究手段。而利用电子探针对矿物中不同价态Fe的含量进行原位定量分析,更是具有非常重要的科学意义。近来发展起来的可进行Fe^(3+) 含量定量分析的电子探针Flank Method测试方法,相比早期的实验方法具有更高的准确度和精确性。该方法主要是通过定义Fe的特征X射线L能级谱线峰位的峰侧位置(flank position),对应了不同价态Fe吸收谱线的差值线谱(difference spectrum)中强度计数最大值(FeLα*)和最小值(FeLβ*)的位置,从而避免了在早期实验中,一般通过直接测量Fe的L能级峰位(FeLα和FeLβ)可能导致的测试不确定性。同时,该测试方法通过对电子探针谱仪系统进行实时的位移误差校正,确保其在某一个稳定的实验条件(周期)下具有可重现性(精确度)。在本文中,我们根据北京大学造山带与地壳演化教育部重点实验室的JEOL JXA-8100型号电子探针的实际性能状态,在前人建立的实验步骤基础上,进行了测试流程的自适性改进和修正,建立了更符合本实验室实际情况的电子探针Flank Method测试方法,用于分析石榴子石中的Fe^(3+) 含量。通过对已知Fe^(3+) 含量的标准石榴子石样品进行检测验证,确定了该方法的可行性、可靠性以及可重复性。在对天然样品的分析中,我们选择了来自我国天山、拉萨和北祁连的洋壳俯冲类型中低温(超)高压榴辉岩中的石榴子石样品,对其进行了Fe^(3+) 含量(环带)的分析。结果显示,石榴子石中Fe^(3+) 含量可作为一个可靠的氧逸度指示剂,其(环带)变化很好地对应了榴辉岩寄主岩石的变质演化轨迹,反映了在板片俯冲过程中,榴辉岩的氧逸度具有降低的趋势。 展开更多
关键词 电子探针 石榴子石 flank Method方法 三价铁
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Identification and isolation of Mu-flanking fragments from maize 被引量:4
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作者 Yijun Wang Guangming Yin +4 位作者 Qin Yang Jihua Tang Xiaomin Lu Schuyler S. Korban Mmghang Xu 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2008年第4期207-213,共7页
Transposable elements have been utilized as mutagens to create mutant libraries for functional genomics. Isolation of genomic segments flanking the insertion Mutator (Mu) is a key step in insertion mutagenesis studi... Transposable elements have been utilized as mutagens to create mutant libraries for functional genomics. Isolation of genomic segments flanking the insertion Mutator (Mu) is a key step in insertion mutagenesis studies. Herein, we adopted a modified AFLP method to identify and isolate Mu-flanking fragments from maize. The method consists of the following steps: 1) double-digestion of genomic DNA with Bgl II/Msp I and ligation of digested fragments to the Bgl II- and Msp I-adaptors; 2) enrichment of a subset of Bgl II/Msp I fragments followed by selective amplification of the Mu-flanking fragments; 3) simultaneous display of AFLP bands derived from the flanking regions for both insert and native Mu transposons; 4) identification and isolation of AFLP bands resulting from Mu insertions by comparing the banding profiles between Mu-induced mutants and their parental lines; and 5) confirmation of flanking fragments related to these Mu insertions. Using this approach, we have isolated flanking fragment(s) resulting from Mu insertion for every Mu-induced mutant, and one such fragment, M196-FF, is found to contain a partial sequence of the DNA topoisomerase I gene Topl. Moreover, the modified AFLP method including all restriction enzymes, adaptors and primers has been optimized in this study. The modified AFLP method has been proved to be simple and efficient in the isolation of Mu-flanking fragments and will find its usefulness in the functional genomics of maize. 展开更多
关键词 Mutator transposon flanking fragment AFLP MAIZE
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Trace and rare earth element geochemistry of the black and grey shales of the Calabar Flank, Southeastern Nigeria: constraints on the depositional environment and the degree of metal enrichment 被引量:1
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作者 Christopher Iorfa Adamu Benjamin Odey Omang +2 位作者 Oluwaseye Peter Oyetade Otu Johnson Therese Ntonzi Nganje 《Acta Geochimica》 EI CAS CSCD 2021年第3期312-324,共13页
This study focuses on the trace and rare earth elements(REE)geochemistry of the Nkporo and Ekenkpon Shales of the Calabar Flank.The main aim is to infer their depositional environment and the degree of their metal enr... This study focuses on the trace and rare earth elements(REE)geochemistry of the Nkporo and Ekenkpon Shales of the Calabar Flank.The main aim is to infer their depositional environment and the degree of their metal enrichment.The shale samples were analyzed using inductively coupled plasma mass spectrometry.The results indicated that the mean concentrations of K,Na,and Fe in Nkporo and Ekenkpon Shales are 1.45,0.4,and 4.17 wt%,and 1.11,0.44,and 5.42 wt%;respectively.The Nkporo Shale is enriched with the following trace elements;P>Mn>Sr>Ba>Zn>Ce>Rb>Zr>V>Cr>Ni and depleted in the following trace elements;Ta>Ge>Sb>Bi>Cd>Ag>Te>In>Hg.While the Ekenkpon Shale is enriched with the following trace elements;P>Mn>Ba>Sr>V>Ce>Zr>Rb>Cr>Zn>Ni and depleted in;Sb>Ge>Bi>Ag>Ce>Te>In>Hg.The concentration of redox-sensitive elements such as V,Ni,Mo,U,Cu,Cr,Re,Cd,Sb,Ti,Mn,and their ratio V/Mo and U/Mo in the black and grey shale samples show different patterns.The REE obtained from the Nkporo and Ekenkpon Shales were PAAS normalized.The Nkporo Shale showed a slightly flat light rare-earth element(LREE),middle rare-earth element(MREE),and heavy rare earth element(HREE)pattern enrichment.Ce/Ce*ranges from 0.95 to 1.09 in Nkporo Shale and 0.67 to 1.40 in Ekenkpon Shale.The Ekenkpon Shale showed a slight LREE,MREE enrichment,and depleted HREE patterns.The Mn contents and U/Mo ratio in Nkporo and Ekenkpon Shales suggests a poor oxygen transitional environment.The V/Mo and V/(V+Ni)ratios indicated that the Nkporo shales were deposited in an anoxic to suboxic conditions and Ekenkpon shales were also deposited under an anoxic to suboxic conditions.The V/Ni ratio indicated that the organic matter in the Nkporo shale is terrigenous while that of the Ekenkpon shales are both terrigenous and marine in origin. 展开更多
关键词 Rare-earth elements(REE) Trace elements Calabar flank SUBOXIC ANOXIC
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Generation of tool path for flank milling in divided areas
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作者 孙春华 刘华明 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2000年第4期31-33,共3页
Presents the division of non developable ruled surface into divided small areas and flank milling in these divided areas to improve machining efficiency and machined surface quality by controlling the machining error ... Presents the division of non developable ruled surface into divided small areas and flank milling in these divided areas to improve machining efficiency and machined surface quality by controlling the machining error for each area, and the algorithms developed for generation of tool path and calculation of errors, and concludes from computer simulation results that the algorithms are correct. 展开更多
关键词 flank MILLING in divided area GENERATION of tool PATH 5 AXIS NC MACHINING
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Reliability of the Brownish-flanked Bush Warbler's soft song in male-male conflict
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作者 Canwei Xia Boye Liu +2 位作者 Daiping Wang Huw Lloyd Yanyun Zhang 《Chinese Birds》 CSCD 2015年第2期107-112,共6页
Background: Soft song is a low-amplitude song produced by many birds. Recent studies have confirmed that soft song is an aggressive signal. For example, the Brownish-flanked Bush Warblers Cettia fortipes use soft song... Background: Soft song is a low-amplitude song produced by many birds. Recent studies have confirmed that soft song is an aggressive signal. For example, the Brownish-flanked Bush Warblers Cettia fortipes use soft song in male-male conflicts, particularly prior to attacks. Although stable signaling systems require that signals be honest on average,models predict that cheating is an acceptable strategy for some individuals or in some contexts.Methods: This study aimed to test the reliability of soft song as an aggressive signal in the brownish-flanked bush warbler. We used mounted specimens accompanied by broadcast songs or soft songs to simulate a male attempting to invade an existing territory.Results: We found the mounted specimen that coupled playback of soft songs suffered more and quicker attacks from the territory owner and that the relationship between soft song and subsequent attack in the territory owner was far from perfect. We observed territory owners that both over-signaled(i.e., produced soft song but did not attack) and under-signaled(i.e., attacked without producing soft song). Under-signaling territory owners were relatively more commonly than were over-signaling territory owners, particularly in simulated intrusion that coupled playback of soft song with a mount specimen.Conclusions: We discuss the cost of producing soft song and the potential benefit of the unreliable use of soft song and propose a new hypothesis for under-signaling with soft song; i.e., under-signaling territory owners might benefit from taking the initiative in fights. 展开更多
关键词 Aggressive signal Brownish-flanked BUSH WARBLER Cost Reliability Soft SONG
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Pattern Recognition for Flank Eruption Forecasting: An Application at Mount Etna Volcano (Sicily, Italy)
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作者 A. Brancato P. M. Buscema +1 位作者 G. Massini S. Gresta 《Open Journal of Geology》 2016年第7期583-597,共16页
A volcano can be defined as a complex system, not least for the hidden clues related to its internal nature. Innovative models grounded in the Artificial Sciences, have been proposed for a novel pattern recognition an... A volcano can be defined as a complex system, not least for the hidden clues related to its internal nature. Innovative models grounded in the Artificial Sciences, have been proposed for a novel pattern recognition analysis at Mt. Etna volcano. The reference monitoring dataset dealt with real data of 28 parameters collected between January 2001 and April 2005, during which the volcano underwent the July-August 2001, October 2002-January 2003 and September 2004-April 2005 flank eruptions. There were 301 eruptive days out of an overall number of 1581 investigated days. The analysis involved successive steps. First, the TWIST algorithm was used to select the most predictive attributes associated with the flank eruption target. During his work, the algorithm TWIST selected 11 characteristics of the input vector: among them SO<sub>2</sub> and CO<sub>2</sub> emissions, and also many other attributes whose linear correlation with the target was very low. A 5 × 2 Cross Validation protocol estimated the sensitivity and specificity of pattern recognition algorithms. Finally, different classification algorithms have been compared to understand if this pattern recognition task may have suitable results and which algorithm performs best. Best results (higher than 97% accuracy) have been obtained after performing advanced Artificial Neural Networks, with a sensitivity and specificity estimates over 97% and 98%, respectively. The present analysis highlights that a suitable monitoring dataset inferred hidden information about volcanic phenomena, whose highly non-linear processes are enhanced. 展开更多
关键词 Mt. Etna Volcano flank Eruption Forecasting Neural Networks Pattern Recognition Monitoring Data
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FLANK DRIVE’Plus开口扳手
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作者 张淑珍 《汽车维修与保养》 2002年第9期16-16,共1页
关键词 flank DRIVE'Plus开口扳手 设计 性能 Snap-on公司
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Genomic structure analysis of SNC6, a progesterone-receptor associated protein gene, and cloning and characterization of its 5'-flanking region 被引量:1
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作者 曹江 郑树 +2 位作者 叶景佳 耿礼义 方永明 《Journal of Zhejiang University Science》 CSCD 2002年第1期100-105,共6页
Objective: To analyze the genomic structure of SNC6, a progesterone-receptor associated protein gene and its regulatory elements in its 5'-flanking region. Methods: Genomic sequence from C, enllank database ( acce... Objective: To analyze the genomic structure of SNC6, a progesterone-receptor associated protein gene and its regulatory elements in its 5'-flanking region. Methods: Genomic sequence from C, enllank database ( accession number: Z98048) covering the whole SNC6 gene was used to analyze the genonfic stnmture of SNC6 and design primers for PCR amplification of its 5'-flanking region. A 1894 bp fragrnem of the 5’-flanking region ( - 1814 to + 75) was cloned by PCR using genomic DNA from a healthy donor peripheral blood lymphocyte as template. This fragment, as well as 3 shorter derivative fragments ( 1423 bp, 632 bp and 416bp, which correspond to - 1344 to + 75, - 552 to + 75 and - 337 to + 75 respectively), were subeloned into pGL2 series luciferase reporter vectors. These constructs were introduced into colorectal cancer cell line SW620 for transient expression of reporter gene and luefferase activities were measured. Results: The genomic structure analysis showed there are 12 exons for SNC6 gene, which spans 32017 bp (nt71529 to nt39513 in Z98048 sequence). All tmnsfected SW620 cells with the above 5-flanking region-containing constructs showed lueiferase activities. The highest lueiferase activities were measured in transfected cells with vectors containing 1894 bp fragments, and the lowest luefferase activities were measured in tmnsfected cells with vectors containing 416 bp fragments, lmeiferase activities were higher in transfected cells with vectors containing 632 bp fragments than that in tmnsfected cells with vectors containing 1423 bp fragments. Conclusion: The basle tran-scription-promoting element (promoter) for SNC6 expression resides between 0 to - 337, and two transcription-enhancing dements (enhancer) resides between - 337 to - 552 and - 1344 to - 1814, whereas one transcription-inhibiting element (silencer) exists between -552 to - 1344. 展开更多
关键词 染色体组结构 SNC6基因 孕激素受体相关蛋白 克隆 DNA序列分析 基因表达调节
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Flank gland-secreted putative chemosignals pertaining to photoperiod,endocrine states,and sociosexual behavior in golden hamsters
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作者 Ying-Juan LIU Da-Wei WANG +2 位作者 Lixing SUN Jin-Hua ZHANG Jian-Xu ZHANG 《Current Zoology》 SCIE CAS CSCD 北大核心 2010年第6期800-812,共13页
Behavioral studies have shown that flank glands are involved in chemical communication in golden hamstersMesocricetus auratus but little chemical analysis has been conducted on volatiles arising from these glands. Usi... Behavioral studies have shown that flank glands are involved in chemical communication in golden hamstersMesocricetus auratus but little chemical analysis has been conducted on volatiles arising from these glands. Using gas chromatography-mass spectrometry, we detected compounds from the flank glands of males, only eight of which were also produced infemales. Based on these chemical data we performed a number of further experiments. By manipulating light we found that malesexposed to short-photoperiods developed smaller flank glands than those exposed to long-photoperiods. Six flank gland volatilesreduced in relative abundance, which possibly coded for reproductive status of males of this seasonally breeding hamster species.Through dyadic encounters, we were able to induce the formation of dominant-subordinate relationships and show that two glandularcompounds became high in relative abundance and may function as dominance pheromones. Castration eliminated allmale-specific compounds resulting from flank glands, but bilateral ovariectomies only affected one compound in females. Oncethese ovariectomized females were treated with testosterone, their glandular compounds resembled those of males, suggestingthese compounds are under the main control of androgen. Two female putative pheromones, tetradecanoic acid and hexadecanoicacid, were used in binary choice tests and were both found to attract males over females. Applying a solution of these pheromonecompounds to adult males also suppressed their agonistic 展开更多
关键词 金黄地鼠 行为学 光周期 内分泌 chem 状态 相对丰度 化合物
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Isolation of T-DNA flanking plant DNA from T-DNAinsertional embryo-lethal mutants of Arabidopsis thaliana by plasmid rescue technique
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作者 YAO XIAO LI JIAN GE SUN, ZHI PING ZHU (Chinese National Laboratory of Plant Molecular Genetics,Shanghai Institute of Plant Physiology, Chinese Academy of Sinica, Shanghai 200032, China) (Present address: 1100 Longwu Road, Shanghai Botanical Garden, Shang 《Cell Research》 SCIE CAS CSCD 1996年第2期125-136,共12页
Three T-DNA insertional embryonic lethal mutants from NASC (The Nottingham Arabidopsis Stock Center)were first checked with their segregation ratio of abortive and normal seeds and the copy number of T-DNA insertion. ... Three T-DNA insertional embryonic lethal mutants from NASC (The Nottingham Arabidopsis Stock Center)were first checked with their segregation ratio of abortive and normal seeds and the copy number of T-DNA insertion. The N4081 mutant has a segregation ratio of 1:3.04in average and one T-DNA insertion site according to our assay It was therefore chosen for further analysis. To isolate the joint fragment of T-DNA and plan DNA, the plasmid rescue technique waJs used. pEL-7, one of plasmids from left border of T-DNA, which contained pBR322 was selected from ampicillin plate. The T-DNA fragment of pEL-7 was checked by restriction enzyme analysis and Southern Blot. Restriction analysis confirmed the presence of known sites of EcoRI, PstI and PvuII on it.For confirming the presence of flanking plant DNA in this plasmid, pEL-7 DNA was labeled and hybridized with wild type and mutant plant DNA. The Southern Blot indicated the hybridization band in both of them. Furthermore, the junction of T-DNA/plant DNA was subcloned into bluescript SK+ and sequenced by Applied Biosystem 373A Sequencer. The results showed the 822 bp fragment contained a 274 bp sequence, which is 99.6%homolog (273bp/274 bp) to Ti plasmid pTi 15955 DNA.Ten bp of left 25 bp border repeat were also found in the juction of T-DNA and Plant DNA.Taken together, pEL-7 should contain a joint fragment of T-DNA and flanking plant DNA. This plasmid DNA could be used for the isolation of plant gene, which will be helpful to elucidate the relationship between gene function and plant embryo development. 展开更多
关键词 拟南芥 T-DNA插入 胚胎致死性突变 植物胚胎 植物DNA 分离方法 质粒抢救法
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Effects of tool flank wear on orthogonal cutting process of aluminum alloy
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作者 袁平 柯映林 《中国有色金属学会会刊:英文版》 CSCD 2006年第A03期1562-1569,共8页
The tool flank begins to wear out as soon as cutting process proceeds. Cutting parameters such as cutting forces and cutting temperature will vary with increasing degree of flank wear. In order to reveal the relations... The tool flank begins to wear out as soon as cutting process proceeds. Cutting parameters such as cutting forces and cutting temperature will vary with increasing degree of flank wear. In order to reveal the relationship between them, the theoretical situations of cutting process were analyzed considering the tool flank wear effect. The variation rules of cutting force, residual stress and temperature distributions along with the tool flank wear were analyzed comparing with the sharp tool tip. Through FEM simulation method, affections of the tool flank wear value VB on cutting forces, residual stress and temperature distributions were analyzed. A special result in this simulation is that the thrust force is more sensitive to tool flank wear, which can be used as a recognition method of tool condition monitoring. The FEM simulation analysis result agrees well with the experimental measuring data in public literatures and some experiments made also by the authors. 展开更多
关键词 铝合金 金属切割 有限元分析 切割温度 应力分析
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Tool path generation for 5-axis flank milling of ruled surfaces with optimal cutter locations considering multiple geometric constraints
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作者 Shuoxue SUN Yuwen SUN Jinting XU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2023年第12期408-424,共17页
Ruled surfaces found in engineering parts are often blended with a constraint surface,like the blade surface and hub surface of a centrifugal impeller.It is significant to accurately machine these ruled surfaces in fl... Ruled surfaces found in engineering parts are often blended with a constraint surface,like the blade surface and hub surface of a centrifugal impeller.It is significant to accurately machine these ruled surfaces in flank milling with interference-free and fairing tool path,while current models in fulfilling these goals are complex and rare.In this paper,a tool path planning method with optimal cutter locations(CLs)is proposed for 5-axis flank milling of ruled surfaces under multiple geometric constraints.To be specific,a concise three-point contact tool positioning model is firstly developed for a cylindrical cutter.Different tool orientations arise when varying the three contact positions and a tool orientation pool with acceptable cutter-surface deviation is constructed using a meta-heuristic algorithm.Fairing angular curves are derived from candidates in this pool,and then curve registration for cutter tip point on each determined tool axis is performed in respect of interference avoidance and geometric smoothness.On this basis,an adaptive interval determination model is developed for deviation control of interpolated cutter locations.This model is designed to be independent of the CL optimization process so that multiple CLs can be planned simultaneously with parallel computing technique.Finally,tests are performed on representative surfaces and the results show the method has advantages over previous meta-heuristic tool path planning approaches in both machining accuracy and computation time,and receives the best comprehensive performance compared to other multi-constrained methods when machining an impeller. 展开更多
关键词 flank milling Tool path Tool orientation pool MACHINING Ruled surface
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耐盐转基因大豆事件AtARA6-A001外源插入片段侧翼序列及其应用
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作者 孙星邈 侯云龙 +3 位作者 王英哲 关诗宇 邱红梅 张玲 《大豆科学》 CAS CSCD 北大核心 2024年第1期29-34,共6页
转基因大豆AtARA6-A001事件采用农杆菌介导大豆遗传转化法获得,其受体为沈农9号,具有耐盐特性,目前已经进入环境释放阶段。为明确该转基因大豆材料的分子特征及其转基因检测方法,推进该转基因事件生物安全评价工作。本研究以转基因大豆A... 转基因大豆AtARA6-A001事件采用农杆菌介导大豆遗传转化法获得,其受体为沈农9号,具有耐盐特性,目前已经进入环境释放阶段。为明确该转基因大豆材料的分子特征及其转基因检测方法,推进该转基因事件生物安全评价工作。本研究以转基因大豆AtARA6-A001为研究对象,利用Southern杂交方法及基因组重测序技术鉴定了外源基因的拷贝数及插入位点的位置和方向。同时利用PCR扩增技术获得了外源T-DNA的左右侧翼序列,并基于左右旁侧序列,建立了转AtARA6基因耐盐大豆A001事件的特异性定性PCR检测方法。此方法能特异性检测转基因大豆植株AtARA6-A001根、茎、叶、花和种子样品,并且能够特异性识别转基因大豆事件的身份,这为后续转基因大豆及其产品的检测和监管提供技术支持。 展开更多
关键词 大豆 转基因 侧翼序列 重测序 定性PCR检测
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周向振动钻削中麻花钻后刀面过快磨损机理试验研究
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作者 陈应舒 陈纯 王楠 《机械设计与制造》 北大核心 2024年第5期262-265,270,共5页
周向振动钻削是一种新型的孔加工方式,麻花钻是实现这种加工的重要工具,然而在现场加工过程中发现,麻花钻后刀面的过快磨损是制约周向振动钻孔质量和钻头寿命的重要因素。基于产品抽样钻孔试验与正交试验,对高速钢麻花钻后刀面的过快磨... 周向振动钻削是一种新型的孔加工方式,麻花钻是实现这种加工的重要工具,然而在现场加工过程中发现,麻花钻后刀面的过快磨损是制约周向振动钻孔质量和钻头寿命的重要因素。基于产品抽样钻孔试验与正交试验,对高速钢麻花钻后刀面的过快磨损失效原因进行了综合分析,探讨了麻花钻后刀面的磨损量与机床参数及钻削工艺参数之间的关系,利用周向振动钻床,对麻花钻后刀面过快磨损的主要影响参数进行了试验研究。研究表明,机床自身的参数与加工的工艺参数对麻花钻后刀面的过快磨损均有影响,其中机床自身参数主要是摆振的弧度及圆频率;工艺参数主要为纵向进给量和钻削速度。 展开更多
关键词 麻花钻后刀面 过快磨损 影响因素 正交试验
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On dry machining of AZ31B magnesium alloy using textured cutting tool inserts
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作者 Shailendra Pawanr Kapil Gupta 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第4期1608-1618,共11页
Magnesium alloys have many advantages as lightweight materials for engineering applications,especially in the fields of automotive and aerospace.They undergo extensive cutting or machining while making products out of... Magnesium alloys have many advantages as lightweight materials for engineering applications,especially in the fields of automotive and aerospace.They undergo extensive cutting or machining while making products out of them.Dry cutting,a sustainable machining method,causes more friction and adhesion at the tool-chip interface.One of the promising solutions to this problem is cutting tool surface texturing,which can reduce tool wear and friction in dry cutting and improve machining performance.This paper aims to investigate the impact of dimple textures(made on the flank face of cutting inserts)on tool wear and chip morphology in the dry machining of AZ31B magnesium alloy.The results show that the cutting speed was the most significant factor affecting tool flank wear,followed by feed rate and cutting depth.The tool wear mechanism was examined using scanning electron microscope(SEM)images and energy dispersive X-ray spectroscopy(EDS)analysis reports,which showed that at low cutting speed,the main wear mechanism was abrasion,while at high speed,it was adhesion.The chips are discontinuous at low cutting speeds,while continuous at high cutting speeds.The dimple textured flank face cutting tools facilitate the dry machining of AZ31B magnesium alloy and contribute to ecological benefits. 展开更多
关键词 Magnesium alloy Dry machining Textured tools flank wear SUSTAINABILITY
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基于接触区域自适应调整的圆弧头立铣刀后刀面磨削轨迹精确计算方法
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作者 刘哲 杨德存 +1 位作者 阳智麾 江磊 《中国机械工程》 EI CAS CSCD 北大核心 2024年第7期1222-1231,1240,共11页
为保证圆弧头立铣刀后刀面的加工精度,提出一种基于接触区域自适应调整的圆弧头立铣刀后刀面磨削轨迹精确计算方法。通过圆弧头立铣刀结构特征分解构建了后刀面的数学模型;通过计算砂轮和后刀面之间的磨削接触区域,自适应修正砂轮姿态,... 为保证圆弧头立铣刀后刀面的加工精度,提出一种基于接触区域自适应调整的圆弧头立铣刀后刀面磨削轨迹精确计算方法。通过圆弧头立铣刀结构特征分解构建了后刀面的数学模型;通过计算砂轮和后刀面之间的磨削接触区域,自适应修正砂轮姿态,避免磨削干涉,实现了后刀面几何参数控制的准确性和一致性,并保证了曲面的光滑连接。最后,在VC++平台算法模块开发的基础上,通过加工仿真和磨削试验验证了该算法的有效性。 展开更多
关键词 圆弧头立铣刀 后刀面 磨削轨迹 接触区域 自适应调节
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Global optimization of tool path for five-axis flank milling with a cylindrical cutter 被引量:23
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作者 DING Han1 & ZHU LiMin2 1 State Key Laboratory of Digital Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan 430074, China 2 School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China 《Science China(Technological Sciences)》 SCIE EI CAS 2009年第8期2449-2459,共11页
In this paper, optimum positioning of cylindrical cutter for five-axis flank milling of non-developable ruled surface is addressed from the perspective of surface approximation. Based on the developed interchangeabili... In this paper, optimum positioning of cylindrical cutter for five-axis flank milling of non-developable ruled surface is addressed from the perspective of surface approximation. Based on the developed interchangeability principle, global optimization of the five-axis tool path is modeled as approximation of the tool envelope surface to the data points on the design surface following the minimum zone criterion recommended by ANSI and ISO standards for tolerance evaluation. By using the signed point-to-surface distance function, tool path plannings for semi-finish and finish millings are formulated as two constrained optimization problems in a unified framework. Based on the second order Taylor approximation of the distance function, a sequential approximation algorithm along with a hierarchical algorithmic structure is developed for the optimization. Numerical examples are presented to confirm the validity of the proposed approach. 展开更多
关键词 FIVE-AXIS flank milling TOOL path OPTIMIZATION TOOL axis trajectory SURFACE SURFACE approximation distance function MINIMAX OPTIMIZATION
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