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排序方式: 共有619条查询结果,搜索用时 46 毫秒
1.
Expanded gamut printing is an approach in color reproduction that expands the color gamut of conventional CMYK printing processes via the use of additional colorants, such as Orange, Green, and Violet inks. This study evaluates the ability of commercial color management software to create an accurate solution for an expanded gamut printing system. In this study, two printing processes were used, an Epson SureColor P9000 inkjet printer/proofer and an HP Indigo 7900 digital production press, both with 7-color expanded gamut ink sets. Software solutions from Alwan, CGS ORIS, ColorLogic, GMG Color, Heidelberg, and Kodak were evaluated. The systems were tested to see how well they could reproduce the colors in the entire PANTONE+ Solid Coated spot color library. It is shown that the solutions are able to reproduce 89% to 94% of the spot colors on the Epson P9000 inkjet printer and 77% to 87% of the library on the Indigo 7900, both to less than two CIEDE2000 (a typical tolerance in label and packaging work). The number of color patches in expanded gamut characterization test charts was noted, as this is still an area of proprietary, nonstandardized working practice. There are many different colorant combinations that can make the same color in expanded gamut printing. The ink build created by the different software solutions was studied, as it relates to press stability through appropriate choice of colorants. Pantone and Adobe provide everyday commercial tools for expanded color workflows. The study identified some issues with products from these companies that could confuse a less-skilled user in a busy production environment. The conclusion of the study is that expanded gamut solutions for spot color printing produce totally acceptable results for digital printing processes; expanded gamut printing is ready, here and now. The findings show that expanded gamut printing can replace cumbersome conventional spot color workflows creating considerable savings and advantages, especially for label and packaging printers. 相似文献
2.
After spontaneous regression of transplanted tumours, marked reduction in number of tumours was found when challenged with isogenic tumour cells. The ALS abrogates this effect. Tumour removal by surgical excision of limb and subsequent time scheduled challenge by tumour cells maximally suppress on the 10th day and continues up to the 42nd day the tumorogenic effect. Splenectomy has no effect if done before a day or 3 days after challenge but marked decrease in tumour development was seen when challenged on the 8th day after splenectomy. Amputation and splenectomy together potentiates tumour formation. Only in tumour extrication, does resistance develop up to the 42nd day from surgery. Challenging at a different site in mice with tumours, resulted in prolongation of the intervals of tumour formation. Challenge after surgical removal of tumour after a time lapse, results in marked reduction in number and size of tumours. Surgical tumour extrication after splenectomy and subsequent challenge on 11th day inhibited tumour formation. Whereas splenectomized tumour bearing mice when challenged at a heterosite did not develop resistance. 相似文献
3.
The scalar transform is a new representation for signals, offering a perspective that is different from the Fourier transform. We introduce the notion of a scalar periodic function. These functions are then represented through the discrete scale series. We also define the notion of a strictly scale-limited signal. Analogous to the Shannon interpolation formula, we show that such signals can be exactly reconstructed from exponentially spaced samples of the signal in the time domain. As an interesting, practical application, we show how properties unique to the scale transform make it very useful in computing depth maps of a scene 相似文献
4.
Hemanshu Bhatt Kimberly Y. Donaldson D. P. H. Hasselman Kenneth Chyung Mark P. Taylor 《Journal of the American Ceramic Society》1991,74(6):1463-1465
A study concerning the effect of fiber orientation on the thermal conductivity of a uniaxial carbon-fiber-reinforced borosilicate glass was conducted. For thin specimens, and thick specimens with specimen sides cut parallel to the fiber direction, the dependence of thermal conductivity on fiber orientation showed excellent agreement with theoretical behavior predicted for a composite infinite in extent. In contrast, the thermal conductivity data for rectangular thick specimens fell well below the data for the thin and angled specimens. For fiber orientation of 45° and higher, at which the heat was directed toward the side of the specimen rather than across, the thermal conductivity values showed excellent agreement with theoretical behavior predicted for a finite composite strip with insulated sides. 相似文献
5.
Several special stability controls, including fast turbine valving are in service at AEP's Rockport generating plant to enhance the plant's transient and voltage stability performance. An account of how these supplementary controls evolved over time to meet changing system needs is provided. An overview of field tests, maintenance practices and operating history of the fast turbine valving equipment is presented. Finally, one of the successful Rockport fast valving events is analyzed in detail, with respect to valve stroke characteristics and electrical response of the Rockport units. This paper emphasizes the lessons learned from the operating experience, which include a need to constantly monitor the adequacy of the special stability control equipment, through regular maintenance and analysis of actual operations 相似文献
6.
Predictive simulation of human walking transitions using an optimization formulation 总被引:1,自引:1,他引:0
Yujiang Xiang Jasbir S. Arora Hyun-Joon Chung Hyun-Jung Kwon Salam Rahmatalla Rajankumar Bhatt Karim Abdel-Malek 《Structural and Multidisciplinary Optimization》2012,45(5):759-772
A general optimization formulation for transition walking prediction using 3D skeletal model is presented. The formulation
is based on a previously presented one-step walking formulation (Xiang et al., Int J Numer Methods Eng 79:667–695, 2009b). Two basic transitions are studied: walk-to-stand and slow-to-fast walk. The slow-to-fast transition is used to connect
slow walk to fast walk by using a step-to-step transition formulation. In addition, the speed effects on the walk-to-stand
motion are investigated. The joint torques and ground reaction forces (GRF) are recovered and analyzed from the simulation.
For slow-to-fast walk transition, the predicted ground reaction forces in step transition is even larger than that of the
fast walk. The model shows good correlation with the experimental data for the lower extremities except for the standing ankle
profile. The optimal solution of transition simulation is obtained in a few minutes by using predictive dynamics method. 相似文献
7.
Hemanshu Bhatt Kimberly Y. Donaldson D. P. II. Hasselman Ramakrishna T. Bhatt 《Journal of the American Ceramic Society》1992,75(2):334-340
The role of an interfacial carbon coating in the heat conduction behavior of a uniaxial silicon carbide nitride was investigated. For such a composite without an interfacial carbon coating the values for the thermal conductivity transverse to the fiber direction agreed very well with the values calculated from composite theory using experimental data parallel to the fiber direction, regardless of the ambient atmosphere. However, for a composite made with carbon-coated fibers the experimental values for the thermal conductivity transverse to the fiber direction under vacuum at room temperature were about a factor of 2 lower than those calculated from composite theory assuming perfect interfacial thermal contact. This discrepancy was attributed to the formation of an interfacial gap, resulting from the thermal expansion mismatch between the fibers and the matrix in combination with the low adhesive strength of the carbon coating. In nitrogen or helium the thermal conductivity was found to be higher because of the contribution of gaseous conduction across the interfacial gap. On switching from vacuum to nitrogen a transient effect in the thermal diffusivity was observed, attributed to the diffusion-limited entry of the gas phase into the interfacial gap. These effects decreased with increasing temperature, due to gap closure, to be virtually absent at 1000°C. 相似文献
8.
The application of conventional observer designs for high-dimensional systems may not always be practical due to high computational requirements or the resulting observers being too sensitive to measurement noise. In order to address these issues, this paper presents two observer design techniques for state estimation of high-dimensional chemical processes. One technique is used for systems with inputs, whereas the other one is specifically geared towards systems that are not excited from the outside. Both of these observers are applicable to linear and with a modification to non-linear systems.The main idea behind the presented observer designs is that a reduced-order observer is implemented instead of a conventional state estimator. The motivation is that subspaces, which are close to being unobservable, cannot be correctly reconstructed in a realistic setting due to measurement noise and inaccuracies in the model. The presented approaches make use of this observation and only reconstruct the parts of the system where accurate state estimation is possible. The observer designs are illustrated on a 30-tray distillation column model. Additionally, it has been shown that the location of process measurements has a major effect on the performance of the presented reduced-order observers. 相似文献
9.
Supported 12-tungstophosphoricacid (12-TPA) and 12-tunstosilicicacid (12-TSA) were used as heterogeneous catalysts for liquid-phase
tert-butylation of m-cresol, an industrial important reaction. Alkylation reactions have been carried out with supported 12-TPA by varying different
parameters such as % loading of 12-tungstophosphoricacid onto support, mole ratio of alcohol to m-cresol, reaction temperature, amount of the catalyst, reaction time and calcination temperature to optimize the conditions.
To see the effect of the acidity on the reaction, the same reaction was studied over supported 12-TSA. Both the catalysts
give 100% selectivity for o-isomer with different % conversion. The difference in catalyst performance of both the catalyst
was correlated with the value of total acidity as well as Bronsted acidity. 相似文献
10.