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991.
Hans Wiese Manfred Curbach Kerstin Speck Silvio Weiland Lars Eckfeldt Torsten Hampel 《Beton- und Stahlbetonbau》2004,99(4):253-261
Verification of Crack Limitation for Circular Cross Section The verification of the crack limitation for circular cross sections such as bored piles is often neglected. In some cases for instance for predominantly bending members the crack limitation is the fundamental proof. Thus all necessary principals for the crack limitation of circular cross sections were provided. The analytical approaches are proved by experiments. There is a good conformance between the theoretical approach provided and the tests. 相似文献
992.
993.
国际放射防护委员会(ICRP)提出了“防护量”这一概念。最常用的防护量,即有效剂量E,用于设定照射限值,并在实用辐射防护中使用,以实现最优化原则。然而,有效剂量不是一个可测量的量,基于此国际辐射单位与测量委员会(ICRU)为外照射的剂量测定提出了一个可测量的量,即实用量,用于估计有效剂量。目前使用的实用量定义于20世纪80年代,当时核工业是职业辐射防护的主要关注点。当前,在其他辐射领域,特别是高能辐射,实用量的不足之处变得很明显:可能高估或低估有效剂量。因此,ICRU和ICRP在全面研究的基础上,为外照射的剂量测定提出了新的实用量,以克服上述缺点。实用量的新定义与防护量(包括有效剂量)的定义更具相关性,特别是使用了相同的仿真体模。当前提出的实用量通过缩小防护量与实用量之间的定义差异简化了辐射防护量体系,并从整体上改进了对有效剂量的估计。本文讨论了提出的新实用量对实际剂量测定的影响。 相似文献
994.
Erwin Laure Matthew Haines Piyush Mehrotra Hans Zima 《Concurrency and Computation》2000,12(4):227-249
Opus is a new programming language designed to assist in coordinating the execution of multiple, independent program modules. With the help of Opus, coarse grained task parallelism between data parallel modules can be expressed in a clean and structured way. In this paper we address the problems of how to build a compilation and runtime support system that can efficiently implement the Opus constructs. Our design considers the often‐conflicting goals of efficiency and modular construction through software re‐use. In particular, we present the system requirements for an efficient Opus implementation, the Opus runtime system, and describe how they work together to provide the underlying services that the Opus compiler needs for a broad class of machines. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
995.
996.
997.
AbstractAlthough fouling is a problem varying in space and time, sizing and assessment of a process apparatus is almost always based on one single integral fouling resistance value. Furthermore, the integral fluid dynamic behavior, e.g. the development of time-dependent pressure drop in a heat exchanger, can be influenced by local constrictions. While it is generally possible to determine the time dependency of the integral fouling behavior, local differences are not taken into consideration at present. Therefore, this paper introduces a metrological, an incremental and a segmental approach to study the local development of crystallization fouling by calcium sulfate in a countercurrent double-pipe heat exchanger. The consecutive approaches allow for thermal, volumetric, gravimetric, and optical fouling investigations, aiming to examine the axial distribution of deposit as well as local differences in the deposit morphology. All methods provided congruent results and local fouling could be described properly. An almost clean surface at the colder end of the heat exchanger and an exponential increase of deposit thickness were observed towards the hot end. Hence, the section near to the hot water inlet turned out to be a key area with regards to increasing fouling mass and structural changes of the layer. 相似文献
998.
Maria T. Lblein Isabel Falke Hans Theodor Eich Burkhard Greve Martin Gtte Fabian M. Troschel 《International journal of molecular sciences》2021,22(21)
In ovarian cancer, therapy resistance mechanisms complicate cancer cell eradication. Targeting Musashi RNA-binding proteins (MSI) may increase therapeutic efficacy. Database analyses were performed to identify gene expression associations between MSI proteins and key therapy resistance and cancer stem cell (CSC) genes. Then, ovarian cancer cells were subjected to siRNA-based dual knockdown of MSI-1 and MSI-2. CSC and cell cycle gene expression was investigated using quantitative polymerase chain reaction (qPCR), western blots, and flow cytometry. Metabolic activity and chemoresistance were assessed by MTT assay. Clonogenic assays were used to quantify cell survival post-irradiation. Database analyses demonstrated positive associations between MSI proteins and putative CSC markers NOTCH, MYC, and ALDH4A1 and negative associations with NOTCH inhibitor NUMB. MSI-2 expression was negatively associated with the apoptosis regulator p21. MSI-1 and MSI-2 were positively correlated, informing subsequent dual knockdown experiments. After MSI silencing, CSC genes were downregulated, while cell cycle progression was reduced. Metabolic activity was decreased in some cancer cells. Both chemo- and radioresistance were reduced after dual knockdown, suggesting therapeutic potential. Dual knockdown of MSI proteins is a promising venue to impede tumor growth and sensitize ovarian cancer cells to irradiation and chemotherapy. 相似文献
999.
1000.