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1.
0 IntroductionThegreatimportanceofnickelelectrochemistryinalkalinemedium ,especiallyforpotentialapplication ,hasattractedmuchattetionofresearcherseithertostudythebehaviorofnickel basedelectrodeitselforitsactivitytowardsothermolecules.Manyreportsshowedthatthenickelbasedelectrodeshaveelectro catalyticactivityforreactionsofappliedinterest,suchaselectro chemicaldeterminationofantioxidantsinfood[1 ] ,detectionofni tricoxide (NO )insolution[2 ] ,electrocatalyticoxidationofmethanol[1 ] ,alcohol[3] ,…  相似文献   
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The visual attention mechanism in the brain was studied among 16 young subjects through the precue-target visual search paradigm using the event-related potentials (ERPs) technique, with the attentive ranges cued with different scales of Chinese words. The results showed that the response time was shortened as the cue scale was reduced, while the amplitudes of the P1 and N1 components of the ERPs increased. These results not only provided the electrophysiological evidence supporting the spotlight theory, but also indicated that the spotlight effect occurred during the early period of the selected attention. Two kinds of separation in the P2 effect were observed. One separation was between the P1 effect and P2 effect, which meant that additional computation was needed when the spatial scale of attention was enlarged; the other was between the left and right hemisphere of the P2 effect, which indicates that the attentive processing of the cue range mainly occurred in the left hemisphere.  相似文献   
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1.INTRODUCTION Sincethefirstpaperonfuzzysetswaspublished,fuzzy logiccontrol(FLC)hasattractedgreatattentionfrom boththeacademicandindustrialcommunities.Much progresshasbeenmadeinsuccessfullyapplyingFLCto industrialcontrolsystems.Manytheoreticalresultsabout stabilityanalysisanddesignoffuzzylogiccontrollersys temshavealsobeenobtained.Amongvariouskindsoffuzzycontrolmethods,manycontroldesignmethodshavebeenproposedon theTakagi Sugeno(T S)fuzzymodel[1].Thebasic ideaofthesemethodsincludestwos…  相似文献   
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Patents are the manifestation of the industry R&D endeavor;therefore, World carbon fiber in-dustry from the perspective of patent analysis is studied .Findings from the analysis show a continual increase of carbon fibers patents since 1969 , and the growth rate began even faster after the year of 2005.Five countries (Japan, China, US, Germany and Korea) took dominant positions in global carbon fibers R&D , and the sum of patents applied in these five countries accounted for 80%of the total patents in the world .Corporations do play an active role in global carbon fibers R&D , and over 60%of patents were applied by corporations .Among them , the top 3 corporations were all from Ja-pan, which had much more patents than the other patent assignees .Furthermore, most corporations were not active in cooperation with others , except Toyota Motor Corp .Global carbon fibers R&D fo-cused on sheet manufacture cloth , core wire layer , heat connect provide and filter activated draw . And there is big difference between Japan and China in the R&D focus .China ’ s corporations have exhibited rapid growth in the number of patent applications in recent years , but there is still a large gap between China and foreign countries in view of global patent layout and influence .By providing the insight into the evolution of global carbon fibers industrial and technological development through the perspective of patent analysis , this study hopes to provide an objective statistic reference for fu-ture policy directions and academic researches .  相似文献   
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The effect of Mg substitution for La on microstructure, hydrogen storage and electrochemical properties of the annealed La_(1-x) Mg_x Ni_3.5(x=0.20, 0.23, 0.25 at%) alloys have been studied. All the samples were mainly composed of(LaMg)_2Ni_7,(LaMg)Ni_3, and LaNi_5 phases. Mg substitution for La changed the phase abundance, but did not change the constitution of all phases, which is con fi rmed by the results of backscattered SEM images and EDS analysis. The P–C isotherms indicated that the La_(1-x) Mg_x Ni_3.5alloys reversibly absorbed and desorbed hydrogen smoothly at 298 K. The hydrogen absorption cyclic stabilities of La_(1-x) Mg_x Ni_3.5alloy after 5 hydrogen absorption/desorption cycles reached the maximum values of91.9% and 96.0% at 298 K and 323 K, respectively. The hydrogen desorption capacity and plateau pressure for the La_(1-x) Mg_x Ni_3.5alloy reached the maximum values of 1.055 H/M and 0.074 MPa, respectively. The desorption capacities of La_(1-x) Mg_x Ni_3.5reached 0.193 H/M and 0.565 H/M in the fi rst minute at 298 K and 323 K, respectively. Electrochemical property measurement indicated that La_(1-x) Mg_x Ni_3.5(x=0.20,0.23, 0.25 at%) alloys possessed excellent activation capability and were completely activated within3 cycles. Discharge capacities of La_(1-x) Mg_x Ni_3.5alloys reached 378.2 m A h/g(x = 0.20 at%), 342.7 m A h/g(x = 0.23 at%), and 369.6 m A h/g(x = 0.25 at%), respectively. Moreover, energy density of La_(1-x) Mg_x Ni_3.5alloy was much larger than that of La_0.80Mg_0.20Ni_3.5 alloy and nearly approaches the maximum value of La0.75Mg0.25Ni3.5. Thus, the La_(1-x) Mg_x Ni_3.5alloy exhibits optimum comprehensive properties of hydrogen storage and electrochemistry.  相似文献   
7.
Luo ZX  Ji Q  Yuan CX 《Nature》2007,450(7166):93-97
Tribosphenic molars of basal marsupials and placentals are a major adaptation, with the protocone (pestle) of the upper molar crushing and grinding in the talonid basin (mortar) on the lower molar. The extinct pseudo-tribosphenic mammals have a reversed tribosphenic molar in which a pseudo-talonid is anterior to the trigonid, to receive the pseudo-protocone of the upper molar. The pseudo-protocone is analogous to the protocone, but the anteriorly placed pseudo-talonid is opposite to the posterior talonid basin of true tribosphenic mammals. Here we describe a mammal of the Middle Jurassic period with highly derived pseudo-tribosphenic molars but predominantly primitive mandibular and skeletal features, and place it in a basal position in mammal phylogeny. Its shoulder girdle and limbs show fossorial features similar to those of mammaliaforms and monotremes, but different compared with those of the earliest-known Laurasian tribosphenic (boreosphenid) mammals. The find reveals a much greater range of dental evolution in Mesozoic mammals than in their extant descendants, and strengthens the hypothesis of homoplasy of 'tribosphenic-like' molars among mammals.  相似文献   
8.
The uniform porous structure makes activated porous carbons(APCs) superior electrode material.Traditionally,APCs are produced by a combination of time-consuming high-temperature heat treatment and activation,with a production time of up to several hours.The produced APCs have relatively low specific surface area(SSA) and porosity.Therefore,the electrochemical performance is poor,which limits its application in high-power energy storage devices.Here,APCs materials are directly synthesized by a hi...  相似文献   
9.
We conducted a genome-wide association study for androgenic alopecia in 1,125 men and identified a newly associated locus at chromosome 20p11.22, confirmed in three independent cohorts (n = 1,650; OR = 1.60, P = 1.1 x 10(-14) for rs1160312). The one man in seven who harbors risk alleles at both 20p11.22 and AR (encoding the androgen receptor) has a sevenfold-increased odds of androgenic alopecia (OR = 7.12, P = 3.7 x 10(-15)).  相似文献   
10.
Allele-specific DNA methylation (ASM) is a hallmark of imprinted genes, but ASM in the larger nonimprinted fraction of the genome is less well characterized. Using methylation-sensitive SNP analysis (MSNP), we surveyed the human genome at 50K and 250K resolution, identifying ASM as recurrent genotype call conversions from heterozygosity to homozygosity when genomic DNAs were predigested with the methylation-sensitive restriction enzyme HpaII. Using independent assays, we confirmed ASM at 16 SNP-tagged loci distributed across various chromosomes. At 12 of these loci (75%), the ASM tracked strongly with the sequence of adjacent SNPs. Further analysis showed allele-specific mRNA expression at two loci from this methylation-based screen--the vanin and CYP2A6-CYP2A7 gene clusters--both implicated in traits of medical importance. This recurrent phenomenon of sequence-dependent ASM has practical implications for mapping and interpreting associations of noncoding SNPs and haplotypes with human phenotypes.  相似文献   
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