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991.
应用分形理论对自然崩解过程中的红层软岩粒度数据进行了分析,得到红层软岩崩解物分数维达到2.6~2.7后其崩解趋于停滞的特点.在研究了液压破碎锤、拖式羊足碾等设备对红层软岩的破碎能力后,基于分形图形构造过程中的“迭代”特征,提出了以“翻松—碾压”动作“迭代”为核心机制的消除红层软岩崩解性机械破碎工艺并在湖南省浏醴高速公路进行了现场破碎试验.对现场破碎过程中软岩粒度数据进行的分数维计算表明:重复2次“翻松—碾压”工艺即可将红层软岩破碎至分数维为2.6~2.7.因此,基于分形迭代特征开发的机械破碎工艺可有效消除红层软岩的崩解性.该方法应用在高速公路施工中可将红层软岩填筑利用范围扩大至上路堤,能取得较好的效益. 相似文献
992.
采用考虑“坏”产出的Malmquist-Luenberger指数测算我国全要素生产率,构建面板平滑转换模型研究技术进步与外商直接投资(FDI)之间的非线性关系.研究结果表明,早期经济发展阶段,由于我国与投资国之间的技术差距过大,“FDI技术溢出效应”并未出现,此时FDI不利于技术进步.随着经济逐渐发展,FDI对技术进步的抑制作用逐渐减弱,并开始转为正的促进作用,而当经济发展到门槛值时,促进作用逐渐明显,“FDI技术溢出效应”出现.此外,人力资本和金融发展程度对技术进步的影响也存在门槛效应,其中,人力资本对技术进步的影响最开始为负,然后转为正,而金融发展程度对技术进步的影响最开始为正,然后转为负. 相似文献
993.
AtWNK9为拟南芥WNK(With no lysine kinase)激酶家族成员,其功能尚不清楚.采用生物信息学和生物学实验相结合的方法,对AtWNK9蛋白结构、亚细胞定位、启动子元件、基因表达模式进行了分析.研究发现,AtWNK9定位在细胞核中;该基因在拟南芥根中高效表达,其表达受ABA,NaCl、葡萄糖、热和冷等非生物胁迫处理强烈诱导.结果表明,AtWNK9为非生物胁迫反应相关基因,并可能参与根的生长发育. 相似文献
994.
XU Kuoxi HU Peizhi~ CAI Lihua College of Chemistry Molecular Sciences Wuhan University Wuhan Hubei China 《武汉大学学报:自然科学英文版》2006,11(3):682-686
0 IntroductionPayrriodminaetiics hoenteer oofc ythcleics m .os tC oambupnoduanndts a cnodn tbaeisntin kgno twhnepyridine ring are widely distributedin nature,principally asenzymes and alkaloids . Pyridine enzymes have been foundintissues of all plants and ani mals examined thus far ,andare derivedfromeither nicotinic acid or Vitamin B6[1].Pyr-idine derivatives are also the building block of many phar-maceuticals with a wide range of functionalities that includeantitubercular compounds ,antivi… 相似文献
995.
WANG Sheng XIONG Qian JIANG Ai-ping XIA Ying-qing XU Peng-gen . School of Electronic Information Wuhan University Wuhan Hubei China . School of Physics Technology Wuhan University Wuhan Hubei China . College of Physical Science Technology Huazhong Normal University Wuhan Hubei China 《武汉大学学报:自然科学英文版》2005,10(2):410-412
,,,.lr.0 IntroductionThe RCS(Radar Cross Section) of a target in the near zone is very important in the various civilian and militaryfields. For a complex target, we dissect it in the near zone tomany small regions and simulate the RCS of the the whole … 相似文献
996.
CHEN Juan LI Hong-lian FENG You-mei WANG Jian-zhi .Department of Biochemistry Molecular Biology Tongji Medical College Huazhong University of Science Technology Wuhan China .Department of Pathophysiology Tongji Medical College Huazhong University of Science Technology Wuhan China 《武汉大学学报:自然科学英文版》2005,10(2)
0 IntroductionNeurofibrillary tangle, primarily composed of thehyperphosphorylated microtubule associatedprotein tau[1], is one of the major neuropathologichallmarks in Alzheimar’s disease (AD). In affectedneurons, the major mechanism o… 相似文献
997.
HU Yao-jun~ WEI Lei~ LIU Shu-nan~ YU Jin-hong~ DING Yi~ . Key Laboratory of MOE for Plant Developmental Biology/College of Life Sciences Wuhan University Wuhan Hubei China . College of Life Sciences Hunan University of Science Technology Xiangtan Hunan China . College of Life Sciences Huazhong Normal University Wuhan Hubei China 《武汉大学学报:自然科学英文版》2005,10(3)
0Introduction Malesterilityisacomplicatedphenomenoninhigherplants,whichestablishesthebiologicalbasisofhetero sisutilizationincropsbreeding,especiallyinrice(Oryzasati vaL.).Themolecularandphysiologicalresearchinplantmalesterility,especiallythediscoveryofth… 相似文献
998.
TAO Ning WU Xu-feng QIU Xiao-ping ZHAO Min TAN Yun WU Xin-xing . Institute of Virology Medical School Wuhan University Wuhan Hubei China . Department of Oncology Zhongnan Hospital Wuhan University Wuhan Hubei China 《武汉大学学报:自然科学英文版》2005,10(4):759-766
0Introduction Cervicalcarcinomaisoneofprevalentmalignancy,itisthesecondmostcommoncancerofwomenintheworld wide(thefirstisbreast cancer).Itisestimatedthatthereare450000newcasesinworldeveryyear,ofwhich80%arein developingcountries.Thereare135000newcasesinChin… 相似文献
999.
Ni Bin |bin Zhao Zheng |yu Xie Shu |guo School of Electronic Information Wuhan University Wuhan Hubei China 《武汉大学学报:自然科学英文版》2003,8(3):847-852
0 IntroductionIthasbeenwellknownthattheformationofIonosphericAlfv啨nResonator(IAR)isforthebreakdownofgeometricop tics.ItscentralregionliesneartheheightofF regionelectrondensitypeak .Andatthetypicalheightof 30 0 0kmexiststhemaximumgradientofAlfv啨nvelocity ,whichleadstothereflec tionofshearAlfv啨nwavesandproducestheupperboundaryoftheresonator.Likewise,thelowerboundaryoftheresonatorformsneartheheightof 2 0 0 30 0km .Thus,she… 相似文献
1000.
Liao Ya-li Yang Yan Cao Yang School of Electronic Information Wuhan University Wuhan Hubei China 《武汉大学学报:自然科学英文版》2003,8(4)
0 IntroductionItisbecomingwellknownthatsignalandimageprocessingaregettinggreatimprovementsinperfor mancebyusingwaveletbasedmethods.Wavelettheoryhasbeenfoundtobeausefulapproachinsignalandimageprocessing .Theresultsofwavelet basedimageanalysismethodsaresuperiortothoseobtainedbyusingtraditionalapproaches[1 ,2 ] .But 2 bandwaveletanaly sisisnotaveryeffectivemethodforfeatureextractionorpatternrecognition ,forthepartitionofhighfre quentbandsisquitecoarserin 2 bandwaveletdecom position ,whichisnot… 相似文献