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181.
182.
针对全复合材料正交格栅/梯形波纹夹芯板的弯曲刚度问题,提出一种基于双变量精确板理论的分析模型.采用均质化理论将两种芯子均等效为正交各向异性连续体,基于双变量高阶剪切变形理论的位移场和最小势能原理推导了夹芯板弯曲平衡微分方程.利用四边简支、对边简支和自由两种边界条件下的弯曲挠度和剪切挠度双变量的求解结果计算了夹芯板整体刚... 相似文献
183.
该文研究了Ω =RM0S (M是左R -模 ,右S -模 ,R ,S都是有单位元的环 )是CESS -环的条件 ,证明了 :若Ω是左CESS -环 ,则R是左CESS -环。该文还证明了 :设Ω是左CESS -环 ,若Q≤RR ,SocQ≤eQ ,则对任意同态Φ :Q→M ,都有同态映射Ψ :R→M ,使得Φ =ιψ。 相似文献
184.
Facing the pressure of fossil energy exhaustion and environment pollution, people begin to search for clean and renewable energy to partly substitute fossil energy and realize sustainable development. As the fourth type of energy, biomass energy has many advantages : wide distribution, large quantity, being renewable, clean, storable and transportable and so on. By adopting thermo-chemical and biochemical technologies, biomass energy can be converted to high quality solid, liquid and gaseous energy products, and provide convenient heat and power energy for human being' s production and daily life. This paper presented the status quo of biomass power generation industry in China and also introduced briefly the future development models. 相似文献
185.
Cellular immune response is a major barrier to xenotransplantation, and cell adhesion is the first step in intercellular recognition.
Flow-cytometric adhesion assay has been used to investigate the differential adhesions of monocyte (Mo), natural killer cell
(NK) and T lymphocyte (T) present within human peripheral blood mononuclear cells (PBMC) to porcine aortic endothelial cells
(PAEC), and to demonstrate the effect of human interferon-γ (hIFN-γ) or/and tumor necrosis factor-α (hTNF-α) pretreatment
of PAEC on their adhesiveness for different PBMC subsets. The preferential sequence for PBMC subset binding to resting PAEC
is Mo, NK and T cells, among which T cells show the slightest adherence; hTNF-α can act across the species, and augment Mo,
NK and T cell adhesion ratios by 40%, 110% and 3 times, respectively. These results confirm at the cell level that host Mo
and NK cells are major participants in the cellular xenograft rejection, thereby, providing a prerequisite for further studying
the human Mo/NK-PAEC interactive mechanisms. 相似文献
186.
基因组变异是个体间疾病易感性和药物反应等表型多样性的遗传基础. 国际人类单体型图(International HapMap)旨在为复杂疾病相关遗传变异的研究提供路线图. 单核苷酸多态性(SNPs)是HapMap的基本要素. SNPs等位基因频率影响连锁不平衡结构、单体型的构建、标签SNPs的筛选, 是影响HapMap精度的主要因素之一. 因此, 次要等位基因频率筛选阈值的选择对图谱精度有深远影响. 迄今大多数研究者选用自定的阈值, 且鲜有针对次要等位基因频率筛选阈值对HapMap精度影响的研究. 为探讨次要等位基因频率筛选阈值对相应HapMap精度的影响, 本研究用中国汉、藏族人群15号染色体中心粒区域基因的测序结果按不同次要等位基因频率筛选阈值(≥0.01, ≥0.05, ≥0.10)将以往的数据分成了3组, 即0.01组、0.05组以及0.10组, 分别构建了3组数据的HapMap, 并比较了各组HapMap精度、关联分析的研究效能及节约/总成本比值. 结果显示, 0.01组有最高的关联分析研究效能(相比0.05组: 汉族, P = 0.019; 藏族, P = 0.029), 并捕获了最多的人群特异性单体型(相比0.05组, P = 0.012). 在所检区域内, 与0.10阈值相比, 0.05阈值并没有显著提高关联分析的研究效能(汉族, P = 0.191; 藏族, P = 1.000)及人群特异性单体型的捕获(P = 0.592). 同时, 在藏族人群中, 0.05与0.10组产生了相同数据的标签SNPs效率、连锁不平衡结构域的数目和平均长度、关联分析研究效能及节约/总成本比值. 结果提示, 较低的次要等位基因频率筛选阈值更适合着重于人群特异性单体型的研究; 不同人群最佳次要等位基因频率筛选阈值可能不尽相同. 由于本研究检测基因数目有限, 这一重要议题仍需更多深入的探讨. 相似文献
187.
Expression and immunolocalisation of odorant-binding and chemosensory proteins in locusts 总被引:7,自引:0,他引:7
Jin X Brandazza A Navarrini A Ban L Zhang S Steinbrecht RA Zhang L Pelosi P 《Cellular and molecular life sciences : CMLS》2005,62(10):1156-1166
We have identified, cloned and expressed a new chemosensory protein (CSP) in the desert locust Schistocerca gregaria belonging to a third sub-class of these polypeptides. Polyclonal antibodies stained a band of 14 kDa, as expected, in the extracts of antennae and palps of the adults, but not in the 4th and 5th instars. In the related species Locusta migratoria, instead, the same antibodies cross-reacted only with a band of apparent molecular mass of 35 kDa in the extract of 1st–5th instars, but not in the adults. The recombinant protein binds the fluorescent probe N-phenyl-1-naphthylamine, but none of the compounds so far reported as pheromones for S. gregaria. The expression of the odorant-binding protein (OBP) and of CSPs of sub-classes I and II was also monitored in antennae, tarsi, palpi, wings and other organs of solitary and gregarious locusts in their nymphal and adult stages. OBP was found to be antenna specific, where it is expressed at least from the 3rd instar in both solitary and gregarious locusts. CSPs, instead, appear to be more ubiquitous, with different expression patterns, according to the sub-class. Immunocytochemistry experiments revealed that OBP is present in the sensillum lymph of sensilla trichodea and basiconica, while CSP-I and CSP-III were found in the outer sensillum lymph of sensilla chaetica and in the sub-cuticular space between epidermis and cuticle of the antenna. Sensilla chaetica on other parts of the body showed the same expression of CSP-I as those on the antenna.Received 11 Janury 2005; received after revision 21 February 2005; accepted 18 March 2005X. Jin and A. Brandazza contributed equally to this work. 相似文献
188.
班长英 《太原师范学院学报(自然科学版)》2005,4(3):67-70
文章介绍了通度的概念和VOF方法的计算原理,采用修正的VOF方法跟踪自由表面,应用改进的三维施主与受主单元模型求解流体体积函数F的输运方程,通过编程模拟计算了容器中具有自由表面的三维、非定常液面波动问题,计算结果与实验分析相吻合。 相似文献
189.
190.
抗热震性能是结构陶瓷材料的重要性能之一.以抗热震断裂参数表征材料的抗热震性能,采用理论与实验相结合的方法,建立了基于抗热震性能的陶瓷复合材料的组分设计模型,并采用计算机辅助优化设计技术求得材料的最优组分.结果表明:当Ti(C,N)和SiC的体积含量分别为10.4%和27.1%时,该材料具有最高的抗热震性能,比纯氧化铝陶瓷提高约55%.在此基础上,利用热压技术制得一种SiC/Ti(C,N)/Al2O3复合陶瓷材料.将该材料制成切削刀具,并在切削实验中通过设计切削条件使得刀具主要承受热载荷和热应力的作用,从而发生热)中击破损.实验发现,SiC/Ti(C,N)/Al2O3复合陶瓷刀具切削淬火钢时的抗热)中击破损性能较纯Al2O3陶瓷提高约62-68%,与抗热震性能设计的理论预测基本吻合.这表明,该设计方法是可行的. 相似文献