67 resultados para C ... f, B ... n.

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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UV-BUV-BUV-B UV-BUV-B UV-BUV-BUV-lampUV-B OTCs1UV-B +C2UV-B +W3UV-B+U4UV-B+U+W UV-BUV-BMDAUV-BOTCs10 cm5 cm1.740.94 UV-BUV-BUV-BUV-BUV-BU+WUV-BCCUV-BUV-B UV-BPnΦPSIIUV-BIIPSIIUV-BPSIIUV-B Enhanced UV-B radiation due to the reduction of O3 layer and global warming induced by increased greenhouse gases in the air have become the two pressing aspects of global climate changes. Moreover, enhanced UV-B radiation and warming have profound and long-term impacts on terrestrial plants and ecosystems, and the studies focusing on the two factors have attracted many attentions. Qinghai-Tibetan Plateau is the third in elevation in the world, and enhanced UV-B radiation and climate warming are especially prominent in this region. Our research located in the main forest belt in the eastern Qinghai-Tibetan Plateau where large areas of subalpine coniferous forests distributed. Based on that, we carried out a research to study the effects of enhanced UV-B radiation and climate warming on seed germination and seedlings growth of seedlings which are the important basic stage in forest regeneration. This research was arranged by a complete factorial design and included two factors (UV-B radiation and temperature) with two levels. The UV-lamps were used to manipulate the supplemental UV-B radiation and open-top chambers (OTCs) were adopted to increase temperature. The four treatments were: (1) C, ambient UV-B without warming; (2) U, enhanced UV-B without warming; (3) W, ambient UV-B with OTCs warming; (4) U+W, enhanced UV-B with OTCs warming. The main results were exhibited as follows: 1. Based on our results in this research, OTCs increased temperature on average 1.74 in air (10 cm above ground) and 0.92 in soil (5 cm beneath ground). Furthermore, OTCs also slightly reduced soil moisture and relative air humidity, however, the differences was not statistically significant. 2. Our results showed that enhanced UV-B had no significant effects on the seeds germination of P. asperata. Enhanced UV-B affected sprouts of P. asperata until the needles unfolded. During two years, enhanced UV-B inhibited the efficiency of the antioxidant defense systems, and as a result, it induced oxidant stress and the accumulation of MDA in needles. After two years of exposure to enhanced UV-B, the growth of P. asperata sprouts was markedly restrained compared with those under ambient UV-B radiation and temperature (C). Warming significantly stimulated the germination speed and increased the germination rate of P. asperata seeds. In the next place, it prominently facilitated the growth of P. asperata sprouts, represented as improvements in stem elongation and biomass accumulation. Furthermore, warming also increased root growth of P. asperata sprouts, which could made sprouts more efficient to use water and nutrient elements in soil. In this research, warming alleviated the deleterious effects of enhanced UV-B on P. asperata sprouts. It markedly stimulated the growth of P. asperata sprouts exposed to enhanced UV-B. The ease effects of warming on the abilities of the antioxidant defense systems might account for its amending effects on growth. After two years of exposure to enhanced UV-B radiation and warming, the growth of P. asperata sprouts was better than those under ambient UV-B radiation without warming (C), which could be seen from the higher plant height, basal diameter, root length and total biomass accumulation compared with C. 3. Enhanced UV-B radiation significantly influenced the photosynthesis processes of two-year old P. asperata seedlings. Our results showed that enhanced UV-B reduced the net photosynthetic rate (Pn) and the apparent quantum efficiency (Φ), and induced photoinhibition of photosynthetic system II (PSII). Enhanced UV-B significantly decreased the concentration of nitrogen (N), phosphorous (P), potassium (K), calcium (Ca), magnesium (Mg) and zinc (Zn), however, it increased the accumulation of iron (Fe) in the whole plant of P. asperata seedlings. Warming significantly stimulated Pn of P. asperata seedlings but it had no prominent impacts on the photochemical efficiency of PSII. In our research, warming also alleviated the harmful effects of enhanced UV-B on photosynthesis and absorption of ions of P. asperata seedlings. It increased Pn, Φ and the photochemical efficiency of PSII in seedlings exposed to enhanced UV-B. Moreover, warming also increased the absorption of ions of the seedlings exposed to enhanced UV-B radiation.

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EVAc,EVBovey(),EVSung,EV13Sung,,~(13)C NMR13SungαS_1S_2S_3S_4~+0ppm,EV~(13)C NMR,EV

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1,2-,(CH_2)gauche,gauche,,γ_1=6.376.41ppm_2=0.01.56ppm,MSE0.16610~(-2)0.3610~(-2)ppm~21,2-

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On the basis of the pseudopotential plane-wave (PP-PW) method in combination with the local density functional theory (LDFT), complete stress-strain curves for the uniaxial loading and uniaxial deformation along the [001] and [111] directions, and the biaxial proportional extension along [010] and [001] for aluminium are obtained. During the uniaxial loading, certain general behaviours of the energy versus the stretch and the load versus the stretch are confirmed; in each case, there exist three special unstressed structures: f.c.c., b.c.c., and f.c.t. for [001]; f.c.c., s.c., and b.c.c. for [111]. Using stability criteria, we find that all of these states are unstable, and always occur together with shear instability, except the natural f.c.c. structure. A Pain transformation from the stable f.c.c. structure to the stable b.c.c. configuration cannot be obtained by uniaxial compression along any equivalent [001] and [111] direction. The tensile strengths are similar for the two directions. For the higher energy barrier of the [111] direction, the compressive strength is greater than that for the [001] direction. With increase in the ratio of the biaxial proportional extension, the stress and tensile strength increase; however, the critical strain does not change significantly. Our results add to the existing ab initio database for use in fitting and testing interatomic potentials.

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<> ? ,(287212,B.C.),(300,B.C.),(384322,B.C.),,西,

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(TorslonalSplit-HopkinsonBar)---1300s~(-1)2600s~(-1),,-,,,

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β-SiC沿[111]Si-C{111}shuffle沿[001]spinodalBorn[001][111]沿[010][001][001]沿[001][111]KRbCs{001}{110}{111}{201}{110}{001}{111}b.c.c.{201}h.c.p.b.c.c.便使

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Femtosecond explosive processes of argon clusters irradiated by linearly chirped ultraintense laser pulses have been investigated by 90 degrees side spectral scattering. The spectral redshift and blueshift, which correlate with the cluster explosion processes have been measured for negatively and positively chirped driving laser pulses, respectively. The evolution of the heated-cluster polarizability indicates that the core of the cluster is shielded from the laser field in the beginning of the explosion and enhanced scattering occurs after the fast explosion initiates. Evidence of resonant heating is found from the coincidence of enhanced scattering with enhanced absorption measured using the transmitted spectra. Anomalously large-size clusters with very low gas density have been observed in this way and can be used as clean and important cluster targets.

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We investigated the effect of cerium oxide on the precipitation of Ag nanoparticles in silicate glass via a femtosecond laser irradiation and successive annealing. Absorption spectra show that Ce3+ ions may absorb part of the laser energy via multiphoton absorption and release free electrons, resulting in an increase of the concentration of Ag atoms and a decrease of the concentration of hole-trapped color centers, which influence precipitation of the Ag nanoparticles. In addition, we found that the formed Ag-0 may reduce Ce4+ ions to Ce3+ ions during the annealing process, which inhibits the growth of the Ag nanoparticles.

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10576525a) CAMPEPCKCAM-PEPCKPEPCKC4PEPCKG6PFBPPEPMn2+b)PEPCC3C4.O2- PSIILOXPSIIQPQc)UV-BUV-BO2NO2-d)δ13C80CO20.7~2.3μl/L/CO2NOXSO2CO2CO24CO2e)DPPH.

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Oryza L.Oryzeae DumortierAABBBBCCCCCCDDEEFFGGHHJJHHKKOryza officinalisBBBBCCCCCCDDEE Oryza officinalisGISH;BCDE . 1;/Fukui et al., 19922-20 70%8;-20 18DNAGISH3 . GISHOryza minutaScilla sinensis (2n = 34)1DNA Oryza minutaScilla sinensis2Scilla sinensis;DNA3DNA . GISH1Oryza minuta, O. punctataO. malampuzhaensisBBCC2Oryza minutaBO. punctataB3O. altaCCDDCD . GISHBCDE1BC;ECEBECED;CD

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1(Nostoc flagelliforme)0.9M77KF686-B686nmF648F666F648F666C-(F'648)-B-B648nm686nm666nmC--B CC-_--B C--B 2( synechococcus leopoliensis 625)0.6M0.3M0.1M77K-B(F'684)C-(F655)(F666)C--B-B-B0.lM0,6M c-c--B-B

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使使β-13- 1. Cryptococcus laurentiiBacillus subtilisC. laurentiiB. subtilisC. laurentiiB. subtilis 2. DeccozilSportakIprodineStrobyR. glutinisDeccozilIprodioneStrobyC. laurentii100 l/LStroby2%w/vSBCC. laurentiiT. pullulans(Penicillium expansumAlternaria alternata)SBCC. laurentiiT. pullulans 3. C. laurentiiB. subtilisβ-13- PALPODPPO 4. 2 mMSA0.2 mMMeJA β-13- PAL PODPPOSAMeJA25C-13-PAL0C2 mMSAMonilinia fructicola;0.2 mMMeJAM. fructicolaMeJAβ-13-PALSA 5. 1 × 108CFU/mlC. laurentii5 × 107CFU/mlC. laurentii0.2 mMMeJA 使0.2 mMMeJAC. laurentiiP. expansum M. fructicola250CMeJAC. laurentiiβ-13-PALPOD 6. PCRβ-13-β-13-cDNAGlu-1Glu-2RT-PCRGlu-1C. laurentii-13-;Glu-2C. laurentii