https://www.selleckchem.com/products/azd5991.html Truffles in the genus Tuber are hypogeus fungi that have a worldwide distribution. Despite this, knowledge about their diversity in the Middle East is very limited. In recent years, large quantities of truffles have been imported from Iran for being sold in Italy. While analyzing certain commercial batches of T. aestivum from Iran, we found some ascomata that resembled T. excavatum but had macro- and micromorphological features that were distinct from this species. They were subglobose, or depressed to slightly irregular, with a conspicuous basal cavity, grayish brown, brown, or pinkish gray, with a minutely papillose peridium. The gleba was pinkish gray in youth, brown at maturity, marbled with cream branched veins. Ascospores were broadly ellipsoid, with an irregular reticulum and distinctive long crests along the longitudinal axis, up to 9 µm high. Analysis of internal transcribed spacer (ITS) and large subunit (LSU) rDNA sequences showed that these specimens form a monphyletic and well-supported taxon within the Excavatum clade. Morphological and molecular analyses supported the proposal of the new species T. iranicum.To improve the reliability and accuracy of dynamic machine in design process, high precision and efficiency of numerical computation is essential means to identify dynamic characteristics of mechanical system. In this paper, a new computation approach is introduced to improve accuracy and efficiency of computation for coupling vibrating system. The proposed method is a combination of piecewise constant method and Laplace transformation, which is simply called as Piecewise-Laplace method. In the solving process of the proposed method, the dynamic system is first sliced by a series of continuous segments to reserve physical attribute of the original system; Laplace transformation is employed to separate coupling variables in segment system, and solutions of system in complex domain can be determined;