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1.
《Journal of the European Ceramic Society》2020,40(8):3348-3353
Large transduction coefficient () is difficult to obtain in piezoelectric ceramics because these two parameters show opposite trends with compositional modifications. Herein, the Pb(Zr0.53Ti0.47)O3 ceramic powders were calcinated under different temperatures (A:830 °C, B:860 °C, and C:890 °C), and then mixed together according to different weight ratios (1A:1B:1C, 1A:2B:1C, 1A:2B:3C and 3A:2B:1C) for ceramics preparation. Both d33 and g33 are improved successfully, and the transduction coefficient with the weight ratio of 1A:2B:3C reaches up to 17,500 × 10−15 m2/N, which is 60 % higher than that with the powders calcinated under 830 °C, and at least twice those of commercial PZT-4, PZT-5A and PZT-8 ceramics. The improved transduction coefficient is owing to the enhanced piezoelectric constant and spontaneous polarization resulted from the increased grain size, relative density and the fraction of tetragonal phase. These results indicate that this is a simple but effective way to tailor the transduction coefficient in piezoelectric ceramics. 相似文献
2.
《Information and Software Technology》2006,48(1):31-42
Traditional testing techniques are not adequate for web-based applications, since they miss their additional features such as their multi-tier nature, hyperlink-based structure, and event-driven feature. Limited work has been done on testing web applications. In this paper, we propose new techniques for white box testing of web applications developed in the .NET environment with emphasis on their event-driven feature. We extend recent work on modeling of web applications by enhancing previous dependence graphs and proposing an event-based dependence graph model. We apply data flow testing techniques to these dependence graphs and propose an event flow testing technique. Also, we present a few coverage testing approaches for web applications. Further, we propose mutation testing operators for evaluating the adequacy of web application tests. 相似文献
3.
《Food Control》2006,17(8):631-636
Recently, DNA-based techniques became very common for the detection of genetically modified organisms (GMOs) in food products. For rapid and easy detection of GMOs, polymerase chain reaction (PCR) screening methods, which amplify common transgenic elements, are applied in routine analysis. Incorporation of PCR and membrane method introduced in this study offer an alternative detection of GMOs. In this study, a total of 32 samples and three certified reference materials were tested for the existence of the 35S promoter of cauliflower mosaic virus (CaMV) and 5-enol-pyruvyl-shikimate-3-phosphate synthase (EPSPS) gene residues. Dot blot screening system introduced in this study can be routinely used as a semi-quantitative screening of GMOs. 相似文献
4.
Yanqiu Shao Jiqing Han Ting Liu Yongzhen Zhao 《International Journal of Speech Technology》2007,10(1):45-55
In real speech, not like lexical words (LWs), prosodic words (PWs) are basic rhythmic units. The naturalness of a Text-to-Speech
(TTS) system is directly influenced by the segmentation of the PWs. Most of the PWs are the combination of several LWs. In
this paper, three Lexical Combination Models are proposed to combine LWs into PWs, including a Directed Acyclic Graph Model,
a Segmentation Model and a Markov Model (MM). To cope with the situation where some long LWs should be segmented into two
or more PWs, a Lexical Split Model (LSM) is applied to the long LWs. Experimental results prove that relatively constant results
with various training data can be obtained from a MM. The Transformation-Based Error Driven Learning (TBED) algorithm, for
its high performance of individual property, is applied in combination with the MM to improve the precision of PW segmentation.
Experiments show that among the three proposed models, the MM combined with TBED and LSM, leads to the best performance, in
which a precision of 93.00% and a recall of 93.23% are achieved. The perception test indicates that by using PWs as the lowest
prosodic units a speech sounds more natural and acceptable than by using LWs.
This paper is supported by NSFC Project (60503071); 973 Natural Basic Research Program of China (2004CB318102); Postdoctor
Science Foundation of P. R. China (20070420275). 相似文献
5.
Ying Ding Chunqing Wang Yanhong Tian Binbin Zhang 《Metallurgical and Materials Transactions A》2006,37(12):1017-1025
in-situ transmission electron microscopy (TEM) tensile tests on as-cast and aged 63Sn37Pb solder alloys were conducted, and the fracture
behavior in nanometer scale ahead of the crack tip was inspected and discussed. Results show that the fracture was completed
by connecting the discontinuous cracks or voids. Dislocation behavior was concentrated along the grain boundaries for as-cast
samples, and displayed mainly as dislocation climb. The crack was intergranular dominated under the lower strain rate. While
remarkable mutual dislocation emission was detected in the aged solder. Transgranular cracks were dominant in the fractured
area, and they propagated by linking up with the nanometer scale cracks ahead of the crack tips under the effective promotion
of the inverse dislocation emission. At the same time, the partial interphase or intergranular cracks in the thinned area
were also found. Under this condition, a new critical stress intensity factor K
c
′ to define the mutual dislocation emission was proposed. 相似文献
6.
Initial geopolymeric reaction processes governing dissolution of solid aluminosilicate particles in alkali solutions have
been investigated using conventional experimental techniques, and the data analysed by speciation predictions of the partial
charge model (PCM). For metakaolin powders activated with 5.0 M NaOH, solid-state nuclear magnetic resonance (NMR) spectra
disclose the existence of monomeric [Al(OH)4]− species after two hours of dissolution, consistent with PCM predictions. However, no equivalent monomeric silicate species
were observed for 5.0–10.0 M NaOH activator solutions characteristic of systems with nominal Si/Al ≤ 1. The apparent absence
of monomeric silicate species suggest rapid condensation of silicate units with [Al(OH)4]− to generate aluminosilicate species, as indicated by the evolution of the shoulder at around −87 ppm in the 29Si NMR spectra. Of the two possible stable silicate species [SiO2(OH)2]2− and [SiO(OH)3]−, the latter appears most likely to condense with [Al(OH)4]− to produce aluminosilicate oligomers, from which larger oligomers subsequently form through further condensation with [Al(OH)4]− leading to a gradual build up of aluminosilicate networks and a lowering of system alkalinity. This dissolution and hydrolysis
sequence at the early stages of synthesis suggests a reaction path wholly consistent with predictions of the partial charge
model. 相似文献
7.
8.
《Automation in Construction》2005,14(3):413-430
Supply chain coordination has become a critical success factor for supply chain management (SCM) and effectively improving the performance of organizations in various industries. Coordination refers to the integration of different parts of an organization or different organizations in supply chain to accomplish a collective set of tasks and to achieve mutual benefits. This paper defines the concepts of construction supply chain (CSC) and construction supply chain management, especially regards construction supply chain management as the coordination of interorganizations decision making in construction supply chain and the integration of key construction business processes and key members involved in construction supply chain. Much research and practice indicate that there still are many problems in construction, most of which are supply chain problems. The research analyzes the problems in construction supply chain. In order to resolve these problems and improving the performance of construction, an agent-based framework for construction supply chain coordination is designed based on the agent technology and multiattribute negotiation and multiattribute utility theory (MAUT). The framework, which integrates the construction organizations in construction supply chain and multiattribute negotiation model into a multiagent system (MAS), provides a solution for supply chain coordination in construction through multiattribute negotiation mechanism on the Internet. Finally, the prototype of the framework is developed and tentatively run based on an imaginary construction project. The trial run reveals the feasibility to implement the agent-based framework for coordination in construction. 相似文献
9.
10.
《Applied Energy》2005,81(3):322-333
The separation of useful chemicals, such as indole from coal tar, is an important subject of research in the field of fossil energy, renewable energy, and utilization of byproducts and waste materials. High-pressure crystallization is one of the proposed separation methods. To understand the process requires detailed knowledge of solid–liquid phase behaviors. Solid–liquid phase equilibrium data of various binary mixtures of indole have been reported in the literature. In the present report, we analyze some of the experimental data with our unified solid–liquid–vapor equation-of-state to see whether our model can be useful for the calculation of solid–liquid equilibria in these organic systems. Good correlations of the data and predictions of phase behavior, at very high pressures, are demonstrated. 相似文献