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Real流媒体技术及其在远程教学中的应用 被引量:43
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作者 曹功靖 王晖 吴玲达 《计算机应用研究》 CSCD 北大核心 2001年第6期106-107,112,共3页
研究目的是希望通过对Real流媒体及其软件开发包的研究,能实现一套以Real系统为平台的远程教育系统,实现同步和异步的远程教学活动。
关键词 real 流媒体技术 远程教学 网络教学 INTERNET
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人民币均衡汇率估计 被引量:43
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作者 王泽填 姚洋 《金融研究》 CSSCI 北大核心 2008年第12期22-36,共15页
本文用购买力平价法估计人民币均衡汇率,通过对184个国家及地区1974~2007年的年度面板数据进行估计,发现人民币自1985年以后一直被低估,2005~2007年人民币被低估的幅度分别为23%、20%和16%。与已有的多数文献相比,这一估计结果显得比... 本文用购买力平价法估计人民币均衡汇率,通过对184个国家及地区1974~2007年的年度面板数据进行估计,发现人民币自1985年以后一直被低估,2005~2007年人民币被低估的幅度分别为23%、20%和16%。与已有的多数文献相比,这一估计结果显得比较适中。本文还检验了估计结果对样本选择和解释变量选择的敏感性,结果证明估计结果具有高度稳健性。对人民币失衡和我国贸易平衡的关系以及人民币向均衡水平调整速度的分析,进一步支持估计结果的合理性。根据估计结果,我们认为应该放慢人民币升值速度,否则会带来一系列消极影响。 展开更多
关键词 实际汇率 汇率失衡
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Real与Media流媒体技术比较 被引量:15
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作者 曹功靖 杨征 +1 位作者 王晖 吴玲达 《计算机应用研究》 CSCD 北大核心 2001年第6期103-105,共3页
通过研究和实例设计,探讨了Real流媒体技术和Media流媒体技术的异同之处,以及在应用当中各自的优缺点。
关键词 real MEDIA 流媒体 多媒体
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Developmental Changes of the FAS and HSL mRNA Expression and Their Effects on the Content of Intramuscular Fat in Kazak and Xinjiang Sheep 被引量:30
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作者 乔永 黄治国 +5 位作者 李齐发 刘振山 郝称莉 石国庆 代蓉 谢庄 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2007年第10期909-917,共9页
Twenty-four male Kazak sheep and 30 Xinjiang fine wool sheep at different ages were selected to investigate the development-dependent expression levels of fatty acid synthase (FAS) gene and hormone-sensitive lipase ... Twenty-four male Kazak sheep and 30 Xinjiang fine wool sheep at different ages were selected to investigate the development-dependent expression levels of fatty acid synthase (FAS) gene and hormone-sensitive lipase (HSL) gene in muscle and their effects on the contents of intramuscular fat (IMF). Longissimus dorsal muscle was sampled to measure IMF and total RNA was extracted to determine FAS and HSL mRNA expression levels by real-time PCR. The results showed that: l) The IMF content increased continuously with growth and showed significant differences (P 〈 0.05) between different age groups in male Kazak sheep, but in Xinjiang fine wool sheep there was no such difference observed. Furthermore, the IMF contents in Kazak were much higher (P 〈 0.01) than that of the other breed from day 30 to 90. 2) FAS mRNA expression level was the highest (P 〈 0.05) on day 0 in Kazak sheep and then declined with growth, in the other breed the gene showed a d‘ecline-rise-decline-rise' expression manner as the animals grew. HSL mRNA expression level had a similar model in two breeds, in Kazak sheep it was the highest on day 0 (P 〈 0.05) and in Xinjiang fine wool sheep on day 30 (P 〈 0.01), then both decreased after this term. 3) In male Kazak sheep, FAS and HSL mRNA expression level were both negatively related to IMF content (r= -0.485 (P = 0.02), r= -0.423 (P = 0.05)), and the ratio of FAS/HSL expression exhibited significantly negatively related IMF contents. In male Xinjiang sheep, there were no obvious relationship between FAS and HSL expression and IMF content (P 〉 0.05). 展开更多
关键词 SHEEP intramuscular fat fatty acid synthase hormone-sensitive lipase real time PCR
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Study on real working performance and overload safety factor of high arch dam 被引量:26
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作者 ZHANG GuoXin,LIU Yi & ZHOU QiuJing Department of Structures and Materials,China Institute of Water Resources and Hydropower Research,Beijing 100038,China 《Science China(Technological Sciences)》 SCIE EI CAS 2008年第S2期48-59,共12页
Considering the fact that high arch dams have problems such as complicated stress,high cost,and hazards after being damaged,this paper intends to study the effects of load,material strength,and safety analysis method ... Considering the fact that high arch dams have problems such as complicated stress,high cost,and hazards after being damaged,this paper intends to study the effects of load,material strength,and safety analysis method on dam safety and working performance of arch dams.In this article,the effects of temperature,self weight exaction way and water loading on structure response are first discussed,and a more reasonable way of considering is then put forward.By taking into consideration the mechanical property of materials and comparing the effects of different yield criteria on overloading safety of high arch dams,this paper concludes that brittle characteristics of concrete should be fully considered when conducting safety assessment for high arch dams to avoid overestimating the bearing capacity of the dams.By comparing several typical projects,this paper works out a safety assessment system of multiple safety and relevant engineering analogical analysis methods,which is closer to the actual situation,and thus is able to assess the response of high arch dam structure in a more comprehensive way,elicit the safety coefficients in different situations,and provide a new way of considering the safety assessment of high arch dams. 展开更多
关键词 high ARCH DAM real working performance SAFETY LOAD strength SAFETY assessment method
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Novel 3-dimensional virtual hepatectomy simulation combined with real-time deformation 被引量:22
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作者 Yukio Oshiro Hiroaki Yano +4 位作者 Jun Mitani Sangtae Kim Jaejeong Kim Kiyoshi Fukunaga Nobuhiro Ohkohchi 《World Journal of Gastroenterology》 SCIE CAS 2015年第34期9982-9992,共11页
AIM:To develop a novel 3-dimensional(3D) virtual hepatectomy simulation software,Liversim,to visualize the real-time deformation of the liver.METHODS:We developed a novel real-time virtual hepatectomy simulation softw... AIM:To develop a novel 3-dimensional(3D) virtual hepatectomy simulation software,Liversim,to visualize the real-time deformation of the liver.METHODS:We developed a novel real-time virtual hepatectomy simulation software program called Liversim. The software provides 4 basic functions:viewing 3D models from arbitrary directions,changing the colors and opacities of the models,deforming the models based on user interaction,and incising the liver parenchyma and intrahepatic vessels based on user operations. From April 2010 through 2013,99 patients underwent virtual hepatectomies that used the conventional software program SYNAPSE VINCENT preoperatively. Between April 2012 and October 2013,11 patients received virtual hepatectomies using the novel software program Liversim; these hepatectomies were performed both preoperatively and at the same that the actual hepatectomy was performed in an operating room. The perioperative outcomes were analyzed between the patients for whom SYNAPSE VINCENT was used and those for whom Liversim wasused. Furthermore,medical students and surgical residents were asked to complete questionnaires regarding the new software.RESULTS:There were no obvious discrepancies(i.e.,the emergence of branches in the portal vein or hepatic vein or the depth and direction of the resection line) between our simulation and the actual surgery during the resection process. The median operating time was 304 min(range,110 to 846) in the VINCENT group and 397 min(range,232 to 497) in the Liversim group(P = 0.30). The median amount of intraoperative bleeding was 510 m L(range,18 to 5120) in the VINCENT group and 470 m L(range,130 to 1600) in the Liversim group(P = 0.44). The median postoperative stay was 12 d(range,6 to 100) in the VINCENT group and 13 d(range,9 to 21) in the Liversim group(P = 0.36). There were no significant differences in the preoperative outcomes between the two groups. Liversim was not found to be clinically inferior to SYNAPSE VINCENT. Both students and surgical residents reported that th 展开更多
关键词 LIVER SURGERY SIMULATION VIRTUAL HEPATECTOMY real-
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Survivin mRNA expression in urine as a biomarker for patients with transitional cell carcinoma of bladder 被引量:15
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作者 HOU Jian-quan HE Jun +2 位作者 WEN Duan-gai CHEN Zi-xing ZENG Jian 《Chinese Medical Journal》 SCIE CAS CSCD 2006年第13期1118-1120,共3页
Transitional cell carcinoma (TCC) of bladder is the most common malignant tumor in uropoiesis system. Up to date, there is still lack of an ideal marker for the diagnosis of TCC except CT and MRI imaging and cystosc... Transitional cell carcinoma (TCC) of bladder is the most common malignant tumor in uropoiesis system. Up to date, there is still lack of an ideal marker for the diagnosis of TCC except CT and MRI imaging and cystoscopy. Cystoscopy is an invasive examination, which increases the possibility of urinary tract infection. Urine cytology has low sensitivity (21%--40%) in diagnosis of bladder cancer, especially for those with medium or high differentiation. The specificity is often affected by factors such as specimen collection, urinary tract infection, etc. Detecting the expression of survivin mRNA in urine by real time-PCR is simple in specimen collection and is sensitive and relatively specific, which provides a simple and noninvasive diagnostic method for TCC. Moreover it allows comparing the gene expression levels at different stages and grades of TCC, which can help define malignancy degree of TCC. 展开更多
关键词 transitional cell carcinoma of bladder SURVIVIN real time-polymerase chain reaction
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Real-time content-aware image resizing 被引量:17
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作者 HUANG Hua FU TianNan +1 位作者 ROSIN Paul L QI Chun 《Science in China(Series F)》 2009年第2期172-182,共11页
Content-aware image resizing is a kind of new and effective approach for image resizing, which preserves image content well and does not cause obvious distortion when changing the aspect ratio of images. Recently, a s... Content-aware image resizing is a kind of new and effective approach for image resizing, which preserves image content well and does not cause obvious distortion when changing the aspect ratio of images. Recently, a seam based approach for content-aware image resizing was proposed by Avidan and Shamir. Their results are impressive, but because the method uses dynamic programming many times, it is slow. In this paper, we present a more efficient algorithm for seam based content-aware iraage resizing, which searches seams through establishing the matching relation between adjacent rows or columns. We give a linear algorithm to find the optimal matches within a weighted bipartite graph composed of the pixels in adjacent rows or columns. Therefore, our method is fast (e.g. our method needs only about 100 ms to reduce a 768x1024 Image's width to 1/3 while Avidan and Shamir's method needs 12 s). This supports immediate image resizing whereas Avidan and Shamir's method requires a more costly pre-processing step to enable subsequent real-time processing. A fast method such as the one proposed will be also needed for future real-time video resizing applications. 展开更多
关键词 content aware image resizing video resizing real time MATCHING
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流媒体技术综述 被引量:16
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作者 李建廷 《现代电子技术》 2005年第3期91-93,共3页
流媒体 (stream ing m edia)是一种新兴的网络传输技术 ,在互联网上实时顺序地传输和播放视 /音频等多媒体内容的连续时基数据流 ,流媒体技术包括流媒体数据采集、视 /音频编解码、存储、传输、播放等领域。本文分别从流媒体的技术原理... 流媒体 (stream ing m edia)是一种新兴的网络传输技术 ,在互联网上实时顺序地传输和播放视 /音频等多媒体内容的连续时基数据流 ,流媒体技术包括流媒体数据采集、视 /音频编解码、存储、传输、播放等领域。本文分别从流媒体的技术原理、传输方式、传输协议等方面对流媒体做出阐述。 展开更多
关键词 流媒体 传输协议 real system WINDOWS MEDIA TECHNOLOGY
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荧光定量PCR方法检测畜肉食品中猪源性成分 被引量:19
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作者 王颖 史艳宇 +2 位作者 刘金华 吕航 王莹 《食品安全质量检测学报》 CAS 2013年第5期1529-1534,共6页
目的建立一种快速、特异、灵敏的猪源性成分检测方法。方法本研究以猪线粒体12S rRNA基因序列为靶位点设计引物和探针,进行荧光定量PCR扩增,建立猪源性成分检测方法;以常见畜禽肉包括羊肉、牛肉、鸡肉、鹅肉、鸭肉、兔肉、马肉、鹿肉等... 目的建立一种快速、特异、灵敏的猪源性成分检测方法。方法本研究以猪线粒体12S rRNA基因序列为靶位点设计引物和探针,进行荧光定量PCR扩增,建立猪源性成分检测方法;以常见畜禽肉包括羊肉、牛肉、鸡肉、鹅肉、鸭肉、兔肉、马肉、鹿肉等参考动物物种作特异性检测;以50 mg/kg羊肉DNA作为稀释液对猪肉DNA进行梯度稀释,做灵敏度检测。结果该方法能够有效对猪源性成分进行快速检测,具有较强的特异性,灵敏度较高(可达0.1μg/kg)并且羊肉成分的存在对猪肉灵敏度检测没有影响。结论该方法特异性强,灵敏度高,可以快速、准确检测畜肉食品中含有的猪源性成分。 展开更多
关键词 猪源性成分 12S RRNA基因 real time PCR 检测
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油用牡丹脂肪酸脱氢酶基因FAD3的克隆与表达分析 被引量:20
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作者 黄兴琳 陆俊杏 +3 位作者 廖冰楠 白辉扬 管丽 张涛 《中国农业科学》 CAS CSCD 北大核心 2017年第10期1914-1921,共8页
【目的】ω-3脂肪酸脱氢酶(ω-3 FAD)为植物脂肪酸生物合成途径中的关键酶,通过对油用牡丹‘凤丹’ω-3 FAD基因结构特征及其在不同组织中的表达模式进行分析,为研究FAD3在油用牡丹‘凤丹’脂肪酸形成过程中的调控提供理论基础。【方法... 【目的】ω-3脂肪酸脱氢酶(ω-3 FAD)为植物脂肪酸生物合成途径中的关键酶,通过对油用牡丹‘凤丹’ω-3 FAD基因结构特征及其在不同组织中的表达模式进行分析,为研究FAD3在油用牡丹‘凤丹’脂肪酸形成过程中的调控提供理论基础。【方法】采用RACE和RT-PCR的方法克隆油用牡丹‘凤丹’ω-3 FAD基因,用Vector NTI Advance 11软件进行序列分析,BLAST进行同源性比较,并用MEGA7.0的邻接法(neighbor-joining,NJ)构建系统进化树,利用在线蛋白质分析工具Ex PASy预测FAD3蛋白的基本参数和特性,利用Phyre2预测蛋白质二级和三级结构,并通过实时荧光定量PCR检测该基因在油用牡丹‘凤丹’不同发育期的种子以及不同组织中的特异性表达情况。【结果】获得油用牡丹‘凤丹’脂肪酸脱氢酶FAD3,命名为FAD3(Gen Bank登录号:KX906966)。序列分析表明该基因c DNA序列全长1 723 bp,其中,开放阅读框1 308 bp,编码435个氨基酸,3′端非编码区长287 bp,5′末端非编码区长99 bp,预测成熟蛋白分子量为49.9 k D,理论等电点(p I)为7.42,N端无信号肽,脂肪系数为83.08,不稳定指数35.67,总水平亲水性为-0.222。经FAD3蛋白的二级结构预测,FAD3以α-螺旋、随机卷曲为主,其次是延伸链、β-转角含量较少;多序列比对结果表明,油用牡丹FAD3氨基酸序列含有2个保守结构域,系统发育分析结果显示‘凤丹’与芍药处于同一分支,其亲缘关系最近。TMHMM和Target P亚细胞定位分析得知,FAD3蛋白有3个跨膜区域,可能定位于内质网中发挥功能。组织特异性结果分析表明,FAD3在‘凤丹’的根、茎、叶、花瓣、雌蕊、雄蕊、种子中均有表达,其中,在叶中表达量最高,雌蕊次之,在雄蕊中表达量最低;不同时期种子中,10 d表达量最高,20 d次之,在60 d中表达量最低。【结论】成功从油用牡丹‘凤丹’中克隆获得FAD3全长c DNA序列,其在‘凤丹’不同组织中呈现出� 展开更多
关键词 油用牡丹 脂肪酸脱氢酶 克隆 实时荧光定量PCR
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Interpolation of Morrey-Campanato and related smoothness spaces 被引量:19
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作者 YUAN Wen SICKEL Winfried YANG DaChun 《Science China Mathematics》 SCIE CSCD 2015年第9期1835-1908,共74页
We study the interpolation of Morrey-Campanato spaces and some smoothness spaces based on Morrey spaces, e. g., Besov-type and Triebel-Lizorkin-type spaces. Various interpolation methods, including the complex method,... We study the interpolation of Morrey-Campanato spaces and some smoothness spaces based on Morrey spaces, e. g., Besov-type and Triebel-Lizorkin-type spaces. Various interpolation methods, including the complex method, the ±-method and the Peetre-Gagliardo method, are studied in such a framework. Special emphasis is given to the quasi-Banach case and to the interpolation property. 展开更多
关键词 Morrey space Campanato space Besov-type space Triebel-Lizorkin-type space real and complex interpolation ±-method of interpolati
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番茄水通道蛋白基因SlAQP的克隆与序列分析 被引量:17
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作者 李仁 吴新新 +5 位作者 李蔚 杨荣超 赵永钦 温常龙 赵冰 郭仰东 《中国农业科学》 CAS CSCD 北大核心 2012年第2期302-310,共9页
【目的】通过分析克隆得到的番茄水通道蛋白SlAQP基因的cDNA全长序列特征、编码蛋白的细胞定位及其在番茄材料Mirco Tom中经干旱胁迫后的表达模式,为进一步研究番茄在逆境下的抗逆机制及加快番茄抗逆育种积累资料。【方法】采用RACE技... 【目的】通过分析克隆得到的番茄水通道蛋白SlAQP基因的cDNA全长序列特征、编码蛋白的细胞定位及其在番茄材料Mirco Tom中经干旱胁迫后的表达模式,为进一步研究番茄在逆境下的抗逆机制及加快番茄抗逆育种积累资料。【方法】采用RACE技术克隆番茄水通道蛋白基因的cDNA全长,结合生物信息学软件分析该基因的编码蛋白特性;利用基因枪转化法将SlAQP基因与GFP融合的瞬时表达载体(SlAQP::GFP)转入洋葱表皮细胞,对该基因进行亚细胞定位;利用Real time-PCR分析该基因在番茄品种Mirco Tom中经干旱胁迫下的表达机制。【结果】SlAQP基因(GenBank登录号:HQ433337)cDNA全长为1 107 bp,编码区含852 bp,共编码283个氨基酸。生物信息学软件分析表明,SlAQP基因含有6个跨膜区,2个NPA单元,其氨基酸残基与MIP家族蛋白保守区序列完全一致,且该基因氨基酸序列与其它物种PIP类质膜型水通道蛋白氨基酸序列具有很高的同源性。11个物种间的聚类分析表明,SlAQP基因编码的蛋白与马铃薯质膜型水通道蛋白遗传距离最近。细胞定位结果确认SlAQP基因编码蛋白在细胞质膜上发挥生物学作用。Southern杂交结果显示,SlAQP基因在番茄基因组DNA中呈单拷贝。Real time-PCR分析结果证实,干旱胁迫下该基因表达量总体呈下降趋势。【结论】对番茄水通道蛋白SlAQP基因在干旱胁迫后的表达模式分析,预示该基因表达受逆境条件的影响,为今后进一步探讨其在干旱胁迫中发挥的作用提供了重要信息。 展开更多
关键词 番茄 水通道蛋白 序列分析 细胞定位 real time-PCR
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刺五加鲨烯合酶基因家族两成员的表达及其与皂苷含量的关系 被引量:15
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作者 邢朝斌 龙月红 +3 位作者 李非非 周秘 修乐山 劳凤云 《西南农业学报》 CSCD 北大核心 2014年第3期1252-1255,共4页
为了探明刺五加鲨烯合酶(SS)基因家族2成员对皂苷含量的作用机制,以actin为内参基因,利用real time PCR技术,分析刺五加不同生长发育时期、不同器官及茉莉酸甲酯(MeJA)处理对SS1、SS2基因表达及皂苷含量的影响。结果表明:刺五加SS基因... 为了探明刺五加鲨烯合酶(SS)基因家族2成员对皂苷含量的作用机制,以actin为内参基因,利用real time PCR技术,分析刺五加不同生长发育时期、不同器官及茉莉酸甲酯(MeJA)处理对SS1、SS2基因表达及皂苷含量的影响。结果表明:刺五加SS基因家族的SS1和SS2在整个生长期和各器官中均有表达,且表达量差异显著(P<0.05),其中,在萌芽期两者的表达量差异最大。SS1在叶片、叶柄和根器官中的表达量显著高于SS2的表达量(P<0.05)。MeJA处理可显著提高SS1和SS2基因的表达量。刺五加SS1的表达量与皂苷含量间的相关系数低,未达显著水平。SS2的表达量与皂苷含量呈显著的正相关关系(P<0.01)。SS2表达量的高低决定了皂苷含量的高低,是刺五加中三萜皂苷生物合成中的关键酶。 展开更多
关键词 刺五加 表达 鲨烯合酶基因 real time PCR 皂苷
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Real-time trajectory planning for UCAV air-to-surface attack using inverse dynamics optimization method and receding horizon control 被引量:15
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作者 Zhang Yu Chen Jing Shen Lincheng 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2013年第4期1038-1056,共19页
This paper presents a computationally efficient real-time trajectory planning framework for typical unmanned combat aerial vehicle (UCAV) performing autonomous air-to-surface (A/S) attack. It combines the benefits... This paper presents a computationally efficient real-time trajectory planning framework for typical unmanned combat aerial vehicle (UCAV) performing autonomous air-to-surface (A/S) attack. It combines the benefits of inverse dynamics optimization method and receding horizon optimal control technique. Firstly, the ground attack trajectory planning problem is mathematically formulated as a receding horizon optimal control problem (RHC-OCP). In particular, an approximate elliptic launch acceptable region (LAR) model is proposed to model the critical weapon delivery constraints. Secondly, a planning algorithm based on inverse dynamics optimization, which has high computational efficiency and good convergence properties, is developed to solve the RHCOCP in real-time. Thirdly, in order to improve robustness and adaptivity in a dynamic and uncer- tain environment, a two-degree-of-freedom (2-DOF) receding horizon control architecture is introduced and a regular real-time update strategy is proposed as well, and the real-time feedback can be achieved and the not-converged situations can be handled. Finally, numerical simulations demon- strate the efficiency of this framework, and the results also show that the presented technique is well suited for real-time implementation in dynamic and uncertain environment. 展开更多
关键词 Air-to-surface attack Direct method Inverse dynamics Motion planning real time control Receding horizon control Trajectory planning Unmanned combat aerial vehicles
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辣椒水通道蛋白基因CaAQP的克隆与序列分析 被引量:15
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作者 陈儒钢 朱文超 +3 位作者 巩振辉 李大伟 尹延旭 逯明辉 《中国农业科学》 CAS CSCD 北大核心 2010年第20期4323-4329,共7页
【目的】分析辣椒水通道蛋白基因CaAQP的序列特征,并研究其在抗寒品种P70中经4℃低温胁迫处理后的表达模式,为探讨辣椒的耐寒机理及辣椒品种耐寒性改良积累资料。【方法】利用RACE技术进行cDNA全长克隆,采用生物信息学软件分析克隆基因... 【目的】分析辣椒水通道蛋白基因CaAQP的序列特征,并研究其在抗寒品种P70中经4℃低温胁迫处理后的表达模式,为探讨辣椒的耐寒机理及辣椒品种耐寒性改良积累资料。【方法】利用RACE技术进行cDNA全长克隆,采用生物信息学软件分析克隆基因的编码蛋白特性,并以4℃低温胁迫处理不同时间的抗寒品种P70为材料,利用Realtime-PCR分析所克隆基因在辣椒低温胁迫前后的表达模式,以25℃处理为对照。【结果】在4℃低温胁迫处理后的耐寒辣椒品种P70叶片中分离到与水通道蛋白基因相关的差异表达片段,并利用RACE技术克隆得到该基因的全长cDNA,命名为CaAQP,登录号为GU116569。序列分析表明,该基因大小为1032bp,含5′非编码区为69bp,3′非编码区为210bp,CDS长753bp,编码250个氨基酸,蛋白分子量为25.7kD。应用生物信息学软件对CaAQP分析表明,CaAQP含有6个跨膜区,有2个NPA单元,其氨基酸残基与MIP家族蛋白保守区序列完全一致。氨基酸序列比对发现,该序列与其它物种TIP类液泡膜水通道蛋白氨基酸序列有很高的同源性。聚类分析表明,CaAQP与番茄液泡膜水通道蛋白遗传距离最近,与禾本科的玉米和大麦遗传距离相对较远。Realtime-PCR分析结果证实,该基因在低温胁迫下呈现下调表达的趋势。【结论】利用cDNA-AFLP并结合RACE技术首次在耐寒辣椒品种中克隆了水通道蛋白基因CaAQP,该基因属于MIP蛋白家族的一员,具有其典型的功能域,表达模式分析表明,该基因在低温胁迫过程中具有重要的调控作用,该研究结果为进一步探讨辣椒逆境胁迫过程中基因表达调控机制提供了重要信息。 展开更多
关键词 辣椒 水通道蛋白 基因克隆 序列分析 real time-PCR
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草莓不同器官中microRNA表达差异研究 被引量:13
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作者 李贺 印东升 +3 位作者 王志刚 黄飞飞 常琳琳 张志宏 《果树学报》 CAS CSCD 北大核心 2009年第5期632-637,共6页
MicroRNA(miRNA)在植物的生长发育过程中起着重要作用。以CTAB法提取的总RNA为模板,通过设计茎环反转录引物,利用实时RT-PCR技术对草莓根系、花托、茎尖和叶片4种器官中的6种miRNA进行了表达差异研究。以草莓叶片中6种miRNA的表达量为1... MicroRNA(miRNA)在植物的生长发育过程中起着重要作用。以CTAB法提取的总RNA为模板,通过设计茎环反转录引物,利用实时RT-PCR技术对草莓根系、花托、茎尖和叶片4种器官中的6种miRNA进行了表达差异研究。以草莓叶片中6种miRNA的表达量为1,差异表达结果显示miR164在草莓花托中高度表达,达到6.615,明显高于根系(0.485)、茎尖(0.371)和叶片(1.000);miR172在茎尖和花托中的表达量都较低,分别为0.029和0.020,在根系中的表达量更低,只有0.0008454;miR167在根系中表达也很低,只有0.053;miR156,miR159和miR165在4种草莓器官中的表达差异不明显。这些结果为进一步验证miRNA基因在草莓植株生长发育过程中的作用奠定了基础。 展开更多
关键词 草莓 MICRORNA real time RT—PCR 表达 器官
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油气管网仿真技术现状与展望 被引量:15
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作者 陈国群 郑建国 +2 位作者 柳建军 彭世垚 张明 《油气储运》 CAS 2014年第12期1278-1281,共4页
随着现代化油气管网的快速发展,管网仿真技术得到长足发展,未来亦将在保障管网安全、高效运行中发挥越来越重要的作用。为此,调研了国内外管网仿真技术发展现状,深入分析了国外仿真软件产品的优点与不足;介绍了国内仿真技术发展动态,国... 随着现代化油气管网的快速发展,管网仿真技术得到长足发展,未来亦将在保障管网安全、高效运行中发挥越来越重要的作用。为此,调研了国内外管网仿真技术发展现状,深入分析了国外仿真软件产品的优点与不足;介绍了国内仿真技术发展动态,国产化仿真软件Real Pipe引领了国内油气管网仿真技术的跨越式发展。针对管网业务发展而不断产生的新需求,提出了仿真技术未来发展与应用的几点展望,有助于驱动仿真软件产品在功能与性能上的升级换代,对仿真技术发展具有一定的指导意义。 展开更多
关键词 油气管网 仿真技术 在线仿真 可视化建模 三维实景仿真 协同仿真平台 real PIPE
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MANUFACTURING AND SERVICES:FROM MASS PRODUCTION TO MASS CUSTOMIZATION 被引量:15
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作者 James M.TIEN 《Journal of Systems Science and Systems Engineering》 SCIE EI CSCD 2011年第2期129-154,共26页
Manufacturing and services constitute two of the five sectors of every country's economy;depending on the maturity of the economy,they are-in terms of employment-typically the two largest sectors.The outputs or produ... Manufacturing and services constitute two of the five sectors of every country's economy;depending on the maturity of the economy,they are-in terms of employment-typically the two largest sectors.The outputs or products of an economy can also be divided into goods products(due to manufacturing,construction,agriculture and mining) and services products.To date,the goods and services products have,for the most part,been mass produced;it is the premise of this paper that recent technological advances-including flexible manufacturing,cloud computing,nanotechnology and smart sensing-can better enable the transformation from mass production to mass customization.We regard mass customization as the simultaneous and real time management of supply and demand chains,based on a taxonomy that can be defined in terms of its underpinning component and management foci.From a components perspective,we first consider the value chain of supplier,manufacturer,assembler,retailer,and customer,and then develop a consistent set of definitions for supply and demand chains based on the location of the customer order penetration point.From a management perspective,we classify the methods that are employed in the management of these chains,based on whether supply and/or demand are flexible or fixed.Interestingly,our management taxonomy highlights a very critical research area at which both supply and demand are flexible,thus manageable.Simultaneous management of supply and demand chains sets the stage for mass customization which is concerned with meeting the needs of an individualized customer market.Simultaneous and real time management of supply and demand chains set the stage for real time mass customization(e.g.,wherein a tailor first laser scans an individual's upper torso and then delivers a uniquely fitted jacket within a reasonable period,while the individual is waiting).The benefits of real time mass customization cannot be over-stated as goods and services become indistinguishable and are co-produced-as "servgoods� 展开更多
关键词 Value chain supply chain demand chain TAXONOMY real time management mass production mass customization MANUFACTURING GOODS SERVICES
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Development of a hybrid photoacoustic and optical monitoring system for the study of laser ablation processes upon the removal of encrustation from stonework 被引量:16
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作者 Athanasia Papanikolaou George JTserevelakis +3 位作者 Kristalia Melessanaki Costas Fotakis Giannis Zacharakis Paraskevi Pouli 《Opto-Electronic Advances》 2020年第2期1-11,共11页
In the context of this work,a prototype hybrid photoacoustic(PA)and optical system for the on-line monitoring of laser cleaning procedures is presented.The developed apparatus has enabled the detection of MHz frequenc... In the context of this work,a prototype hybrid photoacoustic(PA)and optical system for the on-line monitoring of laser cleaning procedures is presented.The developed apparatus has enabled the detection of MHz frequency range acoustic waves generated during the laser ablation process.The intrinsically generated PA signals combined with high resolution optical images provide the opportunity to follow the cleaning process accurately and in real time.Technical mock-ups have been used to demonstrate the potential of this novel technique with emphasis given to applications that refer to the restoration of Cultural Heritage(CH)surfaces.Towards this purpose,the real time monitoring of the laser assisted removal of unwanted encrustation from stonework has been achieved using IR and UV wavelengths.This novel approach has allowed for the precise determination of the critical number of laser pulses required for the elimination of the encrustation layer,while highlighting the dominant ablation mechanisms according to the irradiation wavelength.The promising results obtained using the prototype hybrid PA and optical system can open up new perspectives in the monitoring of laser cleaning interventions,promoting an improved restoration outcome. 展开更多
关键词 photoacoustic monitoring laser cleaning encrusted marble real time monitoring two-wavelengths cleaning
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