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91.
92.
Response characteristics of secondary systems anchored or attached to a primary structure can be strongly dependent upon parameter values assumed for the secondary and primary systems. For design and performance evaluations, it is thus of practical interest to develop sensitivity factors relating response behavior of a secondary system to structural parameter variations.
In this paper, the use of spectral moments as peak response sensitivity factors is proposed when the primary-secondary system is subjected to random loading. It is shown that they provide a consistent and quantitative measure of relative importance of parameter uncertainties in the design and performance evaluation of secondary systems. These results are particularly useful to designers in order to determine the desired dynamic characteristics of secondary systems, and to determine the degree of design response spectrum broadening needed. 相似文献
93.
针对异常SEG-Y格式地震数据磁带由于潮湿粘连、粉尘污染和介质因素导致的数据信息不能读写等原因、经研究、实践探索出了一套用相关设备和软件磁磁带的破损进行恢复、修补、保存等方法,使损失降到最低点。此方法在油田实践应用中,收到良好效果,为油田挽回了巨大损失。 相似文献
94.
Wei Wang Boon-Hee Soong 《Communications Letters, IEEE》2007,11(10):793-795
It is desirable for broadcast operation in wireless ad hoc network to prevent collision and achieve low latency at the same time. In this letter, we propose a greedy broadcast scheduling algorithm based on the graph theory of Maximum Weight Independent Set (MWIS) problem. During each broadcast wave cycle, MWIS is able to find the optimal selection of forwarders so that maximum number of untouched nodes is covered without incurring collision. Numerical results show that this algorithm could produce better performance results than recent 2-step approach. 相似文献
95.
The information-theoretic sum capacity of reverse link CDMA systems with QoS constraints is investigated in this paper. Since the reverse link of CDMA systems are, for a given channel and noise conditions, interference-limited, the sum capacity can be achieved by optimally allocating the transmit powers of the mobile stations with the optimal (Shannon) coding. Unfortunately, the sum capacity is usually achieved via unfair resource allocation. This can be avoided by imposing QoS constraints on the system. The results here show that for a single cell system, the sum capacity can be achieved while meeting the QoS constraints with a semi-bang-bang power allocation strategy. Numerical results are then presented to show the multi-user diversity gain and the impact of QoS constraints. The implication of TDM operation in a practical reverse link CDMA system is also discussed. 相似文献
96.
The biochemical activities that underlie the genetically defined activator and repressor functions of the VIVIPAROUS1 (VP1) protein have resisted in vitro analysis. Here, we show that a glutathione S-transferase (GST) fusion protein, including only the highly conserved B3 domain of VP1, has a highly cooperative, sequence-specific DNA binding activity. GST fusion proteins that include larger regions of the VP1 protein have very low activity, indicating that removal of the flanking protein sequences is necessary to elicit DNA binding in vitro. DNA competition and DNase I footprinting analyses show that B3 binds specifically to the Sph element involved in VP1 activation of the C1 gene, whereas binding to the G-box-type VP1-responsive element is of low affinity and is nonspecific. Footprint analysis of the C1 promoter revealed that sequences flanking the core TCCATGCAT motif of Sph also contribute to the recognition of the Sph element in its native context. The salient features of the in vitro GST-B3 DNA interaction are in good agreement with the protein and DNA sequence requirements defined by the functional analyses of VP1 and VP1-responsive elements in maize cells. 相似文献
97.
98.
Transient Electronics: Wireless Microfluidic Systems for Programmed,Functional Transformation of Transient Electronic Devices (Adv. Funct. Mater. 32/2015)
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99.
S Srinivasan CY Peng S Nair JB Skeath EP Spana CQ Doe 《Canadian Metallurgical Quarterly》1998,204(2):478-487
Hippocampal synapses express two distinct forms of the long-term potentiation (LTP), i.e. NMDA receptor-dependent and -independent LTPs. To understand its molecular-anatomical basis, we produced affinity-purified antibodies against the GluRepsilon1 (NR2A), GluRepsilon2 (NR2B), and GluRzeta1 (NR1) subunits of the N-methyl-D-aspartate (NMDA) receptor channel, and determined their distributions in the mouse hippocampus. Using NMDA receptor subunit-deficient mice as the specificity controls, section pretreatment with proteases (pepsin and proteinase K) was found to be very effective to detect authentic NMDA receptor subunits. As the result of modified immunohistochemistry, all three subunits were detected at the highest level in the strata oriens and radiatum of the CA1 subfield, and high levels were also seen in most other neuropil layers of the CA1 and CA3 subfields and of the dentate gyrus. However, the stratum lucidum, a mossy fibre-recipient layer of the CA3 subfield, contained low levels of the GluRepsilon1 and GluRzeta1 subunits and almost excluded the GluRepsilon2 subunit. Double immunofluorescence with the AMPA receptor GluRalpha1 (GluR1 or GluR-A) subunit further demonstrated that the GluRepsilon1 subunit was colocalized in a subset, not all, of GluRalpha1-immunopositive structures in the stratum lucidum. Therefore, the selective scarcity of these NMDA receptor subunits in the stratum lucidum suggests that a different synaptic targeting mechanism exerts within a single CA3 pyramidal neurone in vivo, which would explain contrasting significance of the NMDA receptor channel in LTP induction mechanisms between the mossy fibre-CA3 synapse and other hippocampal synapses. 相似文献
100.
Several species of the genus Haemophilus are well known etiological agents of pneumonia, meningitis, conjunctivitis, epiglottitis and chancroid. However, identification and speciation of Haemophilus is both time consuming and labor intensive. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI/TOF-MS) has been used by several investigators to profile proteins from intact and disrupted bacteria; consequently, MALDI/TOF-MS has emerged as a powerful tool in diagnostic bacteriology. This paper reports the use of MALDI/TOF-MS as a technique for the rapid identification and speciation of Haemophilus. This technique was used to not only identify the pathogen, H. ducreyi, but also to determine strain differences from different isolates. Mass spectral 'fingerprints' were obtained which permitted the rapid speciation of not only pathogenic forms of Haemophilus, but also those bacteria which are normally regarded as non-pathogenic and members of the normal flora. MALDI/TOF mass spectra can be acquired in 10 min, allowing the identification of Haemophilus spp. within 24 h rather than the 48 h or more needed for traditional bacteriological methods. In addition, these are the first mass spectral fingerprints available in the literature for many of these organisms. 相似文献