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31.
J. Délèze 《Cellular and molecular life sciences : CMLS》1987,43(10):1068-1075
Summary The communicating cell junctions that ensure the electrical and diffusional continuity of the intracellular space in the heart fibres can be switched from their normal conducting, or opened state, to an exceptional non-conducting or closed state. This electrical uncoupling is observed after cell injury in the presence of Ca2+ ions in the extracellular fluid, after metabolic inhibition and in the presence of aliphatic alcohols (C6 to C9). The correlations between electrical uncoupling and gap junction morphology in the heart are briefly reviewed. A decrease of the distance between P-face particles and between the E-face pits has been found in all investigations3,10,16,18,55, but the functional significance of this observation is not understood at present. A quantitatively very similar decrease of the average particle diameter (about –0.7 nm) has been measured in glutaraldehyde-fixed sheep Purkinje fibres16 and in unfixed, quickly frozen rat auricles18 that had been electrically uncoupled by three different procedures. About half of this decrease was reversible on short-term electrical recoupling (within 20 min). It is concluded that a measurable decrease of the connexon diameter correlates with electrical uncoupling. 相似文献
32.
有限元与数学规划相结合的方法在求解极限分析问题时会受到计算规模的限制,难以应用到实际工程问题中.该文引入了一种基于线弹性分析的求解复杂结构极限载荷上、下限的方法--弹性补偿法,同时结合三维有限元分析,求解内压下等径三通的极限载荷.通过与弹塑性分析结果比较发现,简单的弹性补偿法能够较好地评估复杂三维结构的塑性承载能力.计算结果表明,主管腹部的局部减薄缺陷对三通结构的极限承载能力影响最大. 相似文献
33.
姚锋平 《苏州大学学报(医学版)》2004,20(4):1-4
讨论导体材料在中间、超导材料在两边的一维Ginzburg-Landau超导方程组的渐近性态,并证明了当Ginzburg-Landau参数趋于无穷大时方程组的解趋向于一个非线性常微分方程组的解. 相似文献
34.
35.
珠江三角洲污染物对东四口门通量影响分析 总被引:9,自引:0,他引:9
利用珠江三角洲河网区水量数学模型,根据1968年(丰水年)、1976年(平水年)、1982年(枯水年)的水文资料,计算了各典型年落潮时珠江三角洲河网区各节点的分流比;采用1995年珠江三角洲各主要河道纳污量资料,综合考虑落潮条件下的污染物迁移过程,估算了污染物在河道中的降妥量;根据各节点(汊点)的分流比及污染物降解量,分析计算了珠江三角洲河网区主要河道污染物对伶仃洋东四口门污染通量的影响。 相似文献
36.
Gap junctions (GJs) are composed of proteins that form a channel connecting the cytoplasm of adjacent cells. Connexins were
initially considered to be the only proteins capable of GJ formation. Another family of GJ proteins (innexins) were first
found in invertebrates and were proposed to be renamed pannexins after their orthologs were discovered in vertebrates. The
lack of both connexins and pannexins in the genomes of some metazoans suggests that other, still undiscovered GJ proteins
exist. In vertebrates, connexins and pannexins co-exist. Here we discuss whether vertebrate pannexins have a nonredundant
role in animal physiology. Pannexin channels appear to be suited for ATP and calcium signaling and play a role in the maintenance
of calcium homeostasis by mechanisms implicating both GJ and nonjunctional function. Suggested roles in the ischemic death
of neurons, schizophrenia, inflammation and tumor suppression have drawn much attention to exploring the molecular properties
and cellular functions of pannexins.
Received 22 April 2007; received after revision 9 September 2007; accepted 19 September 2007 相似文献
37.
n结型Co3O4/In2O3光催化剂是用共沉淀法制备的.并用X射线衍射对其进行表征。用光催化还原Cr^6+和光催化氧化甲基橙的效率来评价该催化剂的活性。实验分别研究了Co3O4的掺杂比、焙烧温度和焙烧时间对光催化活性的影响。实验结果表明.Co3O4的最佳掺杂比(质量分数)为5%。催化剂的最佳焙烧温度和最佳焙烧时间分别为300℃和2h。在可见光和紫外光的照射下。p-n结型光催化剂Co3O4/In2O3的光催化氧化活性和光催化还原活性均比纯In2O3的高。实验同时还探讨了影响p-n结型光催化剂Co3O4/In2O3催化活性的机理。 相似文献
38.
JingBo Wu DongChao Yi ZhengHao Gu Lin Kang WeiWei Xu Jian Chen PeiHeng Wu 《科学通报(英文版)》2009,54(5):873-876
We adopted double-side fabrication process to prepare intrinsic Josephson junctions (IJJs) based on Bi2Sr2CaCu2O8+x
(BSCCO) single crystals. Using crystal cleavage and double-side argon ion milling, we have successfully fabricated very uniform
IJJs with the thickness of single crystal slice less than 200 nm. Using quasi-optical system, the response of the IJJs to
millimeter wave radiation was studied. With applied magnetic field perpendicular to a-b plane, we have observed Shapiro steps under millimeter wave radiation, and the Josephson oscillation of each junction was
phase-locking.
Supported by the National Natural Science Foundation of China (Grant Nos. 60571007, 10778602, 60721063, 60610050), National
Basic Research Program of China (Grant No. 2006CB601006) and the Fund of Jiangsu Province (Grant No. BK2007713) 相似文献
39.
在考虑绝缘层厚度的基础上,运用Bogoliubov-de Gennes(BdG)方程和Blonder-Tinkham-Klapwijk(BTK)理论模型,计算了含有正常金属调制层的铁磁金属/绝缘层/正常金属/s波超导隧道结(FINS结)中的准粒子输运系数和微分电导。计算结果表明,微分电导随正常金属调制层厚度的变化呈周期性振荡,振荡周期与外加偏压有关;当金属调制层厚度较薄时,邻近效应将导致在金属层中有铁磁性和超导性共存的可能性。 相似文献
40.
魏健文 《华中师范大学学报(自然科学版)》2004,38(3):297-300
以方势垒描述绝缘层,考虑正常金属区域的杂质散射,运用Bogoliubov-deGennes(BdG)方程和Blonder-Tinkham-Klapwijk(BTK)理论,对正常金属/绝缘层/s波超导隧道结(NIS结)中的隧道谱作进一步研究.研究表明:(1)在U0>EF的情况下,微分电导随绝缘层宽度的增加而衰减,偏压不同,衰减的程度不同;(2)衰减能压低能隙电导峰;(3)较小的杂质散射即能在隧道谱的零偏压凹陷峰中感应出一小峰. 相似文献