为了解决复数域下基于QR分解的LLL(A.K.Lenstra,H.W.Lenstra and L.Lovász)算法中复Givens旋转矩形式不统一的问题,文章从复数域下原始LLL算法中Gram-Schmidt系数与QR分解的上三角矩阵R中元素之间的关系出发,证明了上三角矩阵R的...为了解决复数域下基于QR分解的LLL(A.K.Lenstra,H.W.Lenstra and L.Lovász)算法中复Givens旋转矩形式不统一的问题,文章从复数域下原始LLL算法中Gram-Schmidt系数与QR分解的上三角矩阵R中元素之间的关系出发,证明了上三角矩阵R的元素与Gram-Schmidt系数以及Lovász条件之间的等价的关系;从复数的指数形式出发,推导出2种适合LLL算法的复Givens旋转矩阵形式,并证明只有其中一种符合Lovász条件下复Givens旋转矩阵形式。仿真结果表明,采用基于QR分解的复数域LLL算法的MIMO系统相比采用基于Gram-Schmidt正交化LLL算法的MIMO系统具有更好的误比特率性能。展开更多
Plants constantly survey the surrounding environment using several sets of photoreceptors. They can sense changes in the quantity （= intensity） and quality （=wavelength） of light and use this information to adjust...Plants constantly survey the surrounding environment using several sets of photoreceptors. They can sense changes in the quantity （= intensity） and quality （=wavelength） of light and use this information to adjust their physiological responses, growth, and developmental patterns. In addition to the classical photoreceptors, such as phytochromes, crypto- chromes, and phototropins, ZEITLUPE （ZTL）, FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 （FKF1）, and LOV KELCH PROTEIN 2 （LKP2） proteins have been recently identified as blue-light photoreceptors that are important for regulation of the circadian clock and photoperiodic flowering. The ZTL/FKF1/LKP2 protein family possesses a unique combination of domains： a blue-light-absorb- ing LOV （Light, Oxygen, or Voltage） domain along with domains involved in protein degradation. Here, we summarize recent advances in our understanding of the function of the Arabidopsis ZTL/FKF1/LKP2 proteins. We summarize the distinct pho- tochemical properties of their LOV domains and discuss the molecular mechanisms by which the ZTL/FKF1/LKP2 proteins reg- ulate the circadian clock and photoperiodic flowering by controlling blue-light-dependent protein degradation.展开更多
The phototropins phot1 and phot2 are plant blue-light receptors that mediate phototropism, chloroplast movements, stomatal opening, leaf expansion, the rapid Inhibition of hypocotyl growth in etiolated seedlings, and ...The phototropins phot1 and phot2 are plant blue-light receptors that mediate phototropism, chloroplast movements, stomatal opening, leaf expansion, the rapid Inhibition of hypocotyl growth in etiolated seedlings, and possibly solar tracking by leaves in those species in which It occurs. The phototroplns are plasma membrane-associated hydrophilic proteins with two chromophore domains （designated LOV1 and LOV2 for their resemblance to domains In other signaling proteins that detect light, oxygen, or voltage） in their Nterminal half and a classic serine/threonlne kinase domain in their C-terminal half. Both chromophore domains bind flavin mononucleotide （FMN） and both undergo light-activated formation of a covalent bond between a nearby cystelne and the C（4a） carbon of the FMN to form the signaling state. LOV2-cystelnyl adduct formation leads to the release downstream of a tightly bound amphlpathlc α-helix, a step required for activation of the klnase function. This cysteinyl adduct then slowly decays over a matter of seconds or minutes to return the photoreceptor chromophore modules to their ground state. Functional LOV2 is required for light-activated phosphorylation and for various blue-light responses mediated by the phototroplns. The function of LOV1 is still unknown, although It may serve to modulate the signal generated by LOV2. The LOV domain Is an ancient chromophore module found In a wide range of otherwise unrelated proteins In fungi and prokaryotes, the latter Including cyanobacterla, eubacterla, and archaea. Further general reviews on the phototropins are those by Celaya and Liscum （2005） and Christie and Briggs （2005）.展开更多
The "Music of the Heart-2011" charity event, jointly sponsored by the Qingdao People’s Association for Friendship with Foreign Countries, the Italian Embassy in China, the Qingdao General Charity Institute ...The "Music of the Heart-2011" charity event, jointly sponsored by the Qingdao People’s Association for Friendship with Foreign Countries, the Italian Embassy in China, the Qingdao General Charity Institute and the Italy Faith Love Hope Fund, was held in the seaside resort from August 26 to 28. The 800,000 RMB raised through Italian classical music concerts and the auctioning of handiworks made by children in the Qingdao Children Welfare Institution was donated to the facility. All the participants were deeply moved by the charity activities and experienced the profound love from a foreign country.展开更多
地理信息系统(Geographical Information System,GIS)具有强大的空间分析功能。GIS方法建立的模型,可以模拟北极多温冰川Austre Lovénbreen的长时间序列变化。研究发现,GIS方法可以快速有效地获取冰川的冰厚、主流线长度、冰川表...地理信息系统(Geographical Information System,GIS)具有强大的空间分析功能。GIS方法建立的模型,可以模拟北极多温冰川Austre Lovénbreen的长时间序列变化。研究发现,GIS方法可以快速有效地获取冰川的冰厚、主流线长度、冰川表面积和冰川体积,其中冰川体积的变化符合高次常函数变化规律;通过对比GIS方法与Elmer/Ice动力学方法模拟的结果,GIS方法对冰川体积的模拟,在十年至几十年的尺度上可行。GIS方法模拟冰川变化,可以快速定量分析冰川未来一定年限内的厚度、面积、体积、主流线长度等几何参数,简化了冰川变化分析研究的过程。展开更多
文摘为了解决复数域下基于QR分解的LLL(A.K.Lenstra,H.W.Lenstra and L.Lovász)算法中复Givens旋转矩形式不统一的问题,文章从复数域下原始LLL算法中Gram-Schmidt系数与QR分解的上三角矩阵R中元素之间的关系出发,证明了上三角矩阵R的元素与Gram-Schmidt系数以及Lovász条件之间的等价的关系;从复数的指数形式出发,推导出2种适合LLL算法的复Givens旋转矩阵形式,并证明只有其中一种符合Lovász条件下复Givens旋转矩阵形式。仿真结果表明,采用基于QR分解的复数域LLL算法的MIMO系统相比采用基于Gram-Schmidt正交化LLL算法的MIMO系统具有更好的误比特率性能。
文摘Plants constantly survey the surrounding environment using several sets of photoreceptors. They can sense changes in the quantity （= intensity） and quality （=wavelength） of light and use this information to adjust their physiological responses, growth, and developmental patterns. In addition to the classical photoreceptors, such as phytochromes, crypto- chromes, and phototropins, ZEITLUPE （ZTL）, FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 （FKF1）, and LOV KELCH PROTEIN 2 （LKP2） proteins have been recently identified as blue-light photoreceptors that are important for regulation of the circadian clock and photoperiodic flowering. The ZTL/FKF1/LKP2 protein family possesses a unique combination of domains： a blue-light-absorb- ing LOV （Light, Oxygen, or Voltage） domain along with domains involved in protein degradation. Here, we summarize recent advances in our understanding of the function of the Arabidopsis ZTL/FKF1/LKP2 proteins. We summarize the distinct pho- tochemical properties of their LOV domains and discuss the molecular mechanisms by which the ZTL/FKF1/LKP2 proteins reg- ulate the circadian clock and photoperiodic flowering by controlling blue-light-dependent protein degradation.
基金Supported by the National Science Foundation, USA, grants MCB 0091384 and 0444504 to WRB, MCB0444390 to RAB, and by the UK Biotechnology and Biological Sciences Research Council, grant BB/C000366/1 to JMC. Publication of this paper is supported by the National Natural Science Foundation of China （30624808） and Science Publication Foundation of the Chinese Academy of Sciences.
文摘The phototropins phot1 and phot2 are plant blue-light receptors that mediate phototropism, chloroplast movements, stomatal opening, leaf expansion, the rapid Inhibition of hypocotyl growth in etiolated seedlings, and possibly solar tracking by leaves in those species in which It occurs. The phototroplns are plasma membrane-associated hydrophilic proteins with two chromophore domains （designated LOV1 and LOV2 for their resemblance to domains In other signaling proteins that detect light, oxygen, or voltage） in their Nterminal half and a classic serine/threonlne kinase domain in their C-terminal half. Both chromophore domains bind flavin mononucleotide （FMN） and both undergo light-activated formation of a covalent bond between a nearby cystelne and the C（4a） carbon of the FMN to form the signaling state. LOV2-cystelnyl adduct formation leads to the release downstream of a tightly bound amphlpathlc α-helix, a step required for activation of the klnase function. This cysteinyl adduct then slowly decays over a matter of seconds or minutes to return the photoreceptor chromophore modules to their ground state. Functional LOV2 is required for light-activated phosphorylation and for various blue-light responses mediated by the phototroplns. The function of LOV1 is still unknown, although It may serve to modulate the signal generated by LOV2. The LOV domain Is an ancient chromophore module found In a wide range of otherwise unrelated proteins In fungi and prokaryotes, the latter Including cyanobacterla, eubacterla, and archaea. Further general reviews on the phototropins are those by Celaya and Liscum （2005） and Christie and Briggs （2005）.
文摘The "Music of the Heart-2011" charity event, jointly sponsored by the Qingdao People’s Association for Friendship with Foreign Countries, the Italian Embassy in China, the Qingdao General Charity Institute and the Italy Faith Love Hope Fund, was held in the seaside resort from August 26 to 28. The 800,000 RMB raised through Italian classical music concerts and the auctioning of handiworks made by children in the Qingdao Children Welfare Institution was donated to the facility. All the participants were deeply moved by the charity activities and experienced the profound love from a foreign country.
文摘地理信息系统(Geographical Information System,GIS)具有强大的空间分析功能。GIS方法建立的模型,可以模拟北极多温冰川Austre Lovénbreen的长时间序列变化。研究发现,GIS方法可以快速有效地获取冰川的冰厚、主流线长度、冰川表面积和冰川体积,其中冰川体积的变化符合高次常函数变化规律;通过对比GIS方法与Elmer/Ice动力学方法模拟的结果,GIS方法对冰川体积的模拟,在十年至几十年的尺度上可行。GIS方法模拟冰川变化,可以快速定量分析冰川未来一定年限内的厚度、面积、体积、主流线长度等几何参数,简化了冰川变化分析研究的过程。
