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1.
Catalysis Letters - Industrial Cu/ZnO/Al2O3 or novel rate catalysts, prepared with a photochemical deposition method, were studied under functional CH3OH synthesis conditions at the set temperature...  相似文献   
2.
In recent years, the computational power of modern processors has been increasing mainly because of the increase in the number of processor cores. Computationally intensive applications can gain from this trend only if they employ parallelism, such as thread-level parallelization. Geometric simulations can employ thread-level parallelization because the main part of a geometric simulation can be divided into a subset of mutually independent tasks. This approach is especially interesting for acoustic beam tracing because it is an intensive computing task. This paper presents the parallelization of an existing beam-tracing simulation composed of three algorithms. Two of them are iterative algorithms, and they are parallelized with an already known technique. The most novel method is the parallelization of the third algorithm, the recursive octree generation. To check the performance of the multi-threaded parallelization, several tests are performed using three different computer platforms. On all of the platforms, the multi-threaded octree generation algorithm shows a significant speedup, which is linear when all of the threads are executed on the same processor.  相似文献   
3.
Nonisothermal crystallization of poly(N‐methyldodecano‐12‐lactam) (MPA) was investigated using DSC method at cooling rates of 2–40 K/min. With increasing cooling rate, crystallization exotherms decreased in magnitude and shifted toward lower temperatures. Subsequent heating runs (10 K/min) showed an exotherm just above Tg, which increased in magnitude with the rate of preceding cooling run, corresponding to the continuation of primary crystallization interrupted as the system crossed Tg on cooling. Kinetic evaluation by the Avrami method gave values of exponent n close to 2.0, suggesting two‐dimensional crystal growth combined with heterogeneous nucleation. The Tobin method, covering the intermediate range of relative crystallinities, provided n ? 2.20, suggesting possible partial involvement of homogeneous nucleation at later stages of nonisothermal crystallization. The crystallization rate parameter k1/n showed a linear dependency on cooling rate for both methods, the Tobin values being slightly higher. The Ozawa approach failed to provide reasonable values of the kinetic exponent m of MPA. The Augis–Bennet method was used to determine the effective activation energy of the entire nonisothermal crystallization process of MPA. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 564–572, 2005  相似文献   
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Aortic aneurysm is a deceptively indolent disease that can cause severe complications such as aortic rupture and dissection. In the normal aorta, vascular smooth muscle cells within the medial layer produce and sustain the extracellular matrix (ECM) that provides structural support but also retains soluble growth factors and regulates their distribution. Although the ECM is an obvious target to identify molecular processes leading to structural failure within the vessel wall, an in-depth proteomics analysis of this important sub-proteome has not been performed. Most proteomics analyses of the vasculature to date used homogenized tissue devoid of spatial information. In such homogenates, quantitative proteomics comparisons are hampered by the heterogeneity of clinical samples (i.e. cellular composition) and the dynamic range limitations stemming from highly abundant cellular proteins. An unbiased proteomics discovery approach targeting the ECM instead of the cellular proteome may decipher the complex, multivalent signals that are presented to cells during aortic remodelling. A better understanding of the ECM in healthy and diseased vessels will provide important pathogenic insights and has potential to reveal novel biomarkers.  相似文献   
6.
The paper presents an improved e-learner model that supports monitoring of user behavior related to information security. The model is built upon standardized IMS specification, according to literature research and survey conducted among e-learners. It is positioned as key part of an extended LTSA architecture in which the learner data is used to improve learner security position by continuous delivery of important information and adapting security mechanisms. The implementation is considered in Moodle LMS.  相似文献   
7.
This Extended Technical Note shows that the final accuracy level of reverse engineered surfaces depends on scanning distance and scanning angle of the laser beam, hence it also depends on the morphology of the scanned objects. On scanning strongly curved objects, such as the ones with free form surfaces, the distance and impact angle of the laser beam are changing continuously during the scanning process. On the basis of these, two critical parameters are specified for the design model, which make it possible to predict these two factors in advance, depending on the morphology of the scanned object. First, a mathematical-statistical design model of the scanning process is generated, which relies on ANOVA (analysis of variance) and DOE (design of experiments). In the next step, a fitness function is optimized by the genetic algorithm (GA) program. This optimization improves the accuracy of the final scanned surfaces, in terms of the minimum standard deviation values of reverse engineered 3D surface model. The proposed approach was confirmed in a case study, which is presented at the end of this Technical Note.  相似文献   
8.
It is essential for product software companies to decide which requirements should be included in the next release and to make an appropriate time plan of the development project. Compared to the extensive research done on requirement selection, very little research has been performed on time scheduling. In this paper, we introduce two integer linear programming models that integrate time scheduling into software release planning. Given the resource and precedence constraints, our first model provides a schedule for developing the requirements such that the project duration is minimized. Our second model combines requirement selection and scheduling, so that it not only maximizes revenues but also simultaneously calculates an on-time-delivery project schedule. Since requirement dependencies are essential for scheduling the development process, we present a more detailed analysis of these dependencies. Furthermore, we present two mechanisms that facilitate dynamic adaptation for over-estimation or under-estimation of revenues or processing time, one of which includes the Scrum methodology. Finally, several simulations based on real-life data are performed. The results of these simulations indicate that requirement dependency can significantly influence the requirement selection and the corresponding project plan. Moreover, the model for combined requirement selection and scheduling outperforms the sequential selection and scheduling approach in terms of efficiency and on-time delivery.  相似文献   
9.
A modified design approach for compact ultra‐wideband microstrip filters with cascaded/folded stepped‐impedance resonators is described. The key feature of the proposed method is to facilitate stronger coupling between stepped‐impedance resonators and, at the same time, eliminate the requirement of extremely small gaps in coupled‐line sections, as found in traditional designs. Simulations and measurements demonstrate that the filters designed with this technique exhibit good reflection, insertion‐loss, and group‐delay performance within the 3.1–10.6 GHz band. © 2009 Wiley Periodicals, Inc. Int J RF and Microwave CAE 2010.  相似文献   
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