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排序方式: 共有187条查询结果,搜索用时 31 毫秒
1.
Microsystem Technologies - The quantitative analysis of microwave noise available in the double gate (DG) high electron transistors of mobility (HEMT) is reported in this paper. For this analysis,...  相似文献   
2.
The fracture toughness of a canasite glass-ceramic with a highly acicular, interlocked grain structure was measured by a number of different methods. The values at room temperature obtained by the chevron-notch, short-bar and notched-beam methods ranged from 4 to 5 M Pa m–1/2, well above literature values for other glass-ceramics. Similar values of toughness were obtained by the fracture of bars with indentation cracks introduced with loads ranging from 1.96 to 400 N, but only for crack sizes >200 m, with lower values for cracks of smaller size. The toughness values obtained by the direct measurement of the size of the indentation cracks were appreciably lower than the values obtained by all other methods over the total range of indentation loads and corresponding crack size. SEM fractography showed that the surface within the indentation cracks was appreciably smoother than the surrounding fracture surface. The high values of fracture toughness were attributed to the combined mechanisms of crack-deflection and microcrack-toughening due to the stress-enhanced creation of microcracks caused by the residual stresses which arise from the thermal expansion anisotropy of the canasite monoclonic crystal structure. The strong negative temperature dependence of the fracture toughness suggests that at room temperature microcrack toughening represents the primary contributing mechanism to the fracture toughness. The combined effects of crack-deflection and microcrack-toughening can lead to the development of glass-ceramics with greatly improved resistance to crack propagation.  相似文献   
3.
Indian diets comprising staples such as cereals, millets, and pulses provide 4.8 energy % from linoleic acid (18∶2n−6) but fail to deliver adequate amounts of n−3 FA. Consumption of long-chain n−3 PUFA such as EPA (20∶5n−3) and DHA (22∶6n−3) is restricted to those who consume fish. The majority of the Indian population, however, are vegetarians needing additional dietary sources of n−3 PUFA. The present work was designed to use n−3 FA-enriched spray-dired milk powder to provide n−3 FA. Whole milk was supplemented with linseed oil to provide α-linolenic acid (LNA, 18∶3n−3), with fish oil to provide EPA and DHA, or with groundnut oil (GNO), which is devoid of n−3 PUFA, and then spray-dired. Male Wistar rats were fed the spray-dired milk formulations for 60 d. The rats given formulations containing n−3 FA showed significant increases (P<0.001) in the levels of LNA or EPA/DHA in the serum and in tissue as compared with those fed the GNO control formulation. Rats fed formulations containing n−3 FA had 30–35% lower levels of serum total cholesterol and 25–30% lower levels of serum TAG than control animals. Total cholesterol and TAG in the livers of rats fed the formulations containing n−3 FA were lower by 18–30% and 11–18%, respectively, compared with control animals. This study showed that spray-dried milk formulations supplemented with n−3 FA are an effective means of improving dietary n−3 FA intake, which may decrease the risk factors associated with cardiovascular disease.  相似文献   
4.

This paper first presents a novel approach for modelling facial features, Local Directional Texture (LDT), which exploits the unique directional information in image textures for the problem of face recognition. A variant of LDT with privacy-preserving temporal strips (TS) is then considered to achieve faceless recognition with a higher degree of privacy while maintaining high accuracy. The TS uses two strips of pixel blocks from the temporal planes, XT and YT, for face recognition. By removing the reliance on spatial context (i.e., XY plane) for this task, the proposed method withholds facial appearance information from public view, where only one-dimensional temporal information that varies across time are extracted for recognition. Thus, privacy is assured, yet without impeding the facial recognition task which is vital for many security applications such as street surveillance and perimeter access control. To validate the reliability of the proposed method, experiments were carried out using the Honda/UCSD, CK+, CAS(ME)2 and CASME II databases. The proposed method achieved a recognition rate of 98.26% in the standard video-based face recognition database, Honda/UCSD. It also offers a 81.92% reduction in the dimension length required for storing the extracted features, in contrast to the conventional LBP-TOP.

  相似文献   
5.
This paper explores the increasing trend towards the commodification of public research and development (R&D) and the impact of this on social wellbeing. In many developed countries, the changes introduced by governments to funding mechanisms for universities and public research institutions has led to a fundamental shift in the focus of public R&D. The focus has shifted from creating useful public, codifiable knowledge to creating a knowledge commodity driven by commercial imperatives. Although there may be an economic argument to be made for the virtues of such change, we argue here that the potential costs to social wellbeing have been largely, and dangerously, ignored.
Rebecca BodenEmail:
  相似文献   
6.
Ant Colony Optimization (ACO) is a Swarm Intelligence technique which inspired from the foraging behaviour of real ant colonies. The ants deposit pheromone on the ground in order to mark the route for identification of their routes from the nest to food that should be followed by other members of the colony. This ACO exploits an optimization mechanism for solving discrete optimization problems in various engineering domain. From the early nineties, when the first Ant Colony Optimization algorithm was proposed, ACO attracted the attention of increasing numbers of researchers and many successful applications are now available. Moreover, a substantial corpus of theoretical results is becoming available that provides useful guidelines to researchers and practitioners in further applications of ACO. This paper review varies recent research and implementation of ACO, and proposed a modified ACO model which is applied for network routing problem and compared with existing traditional routing algorithms.  相似文献   
7.
Intestinal carotenoid absorption is greatly affected by dietary factors. In this study, it was hypothesized that lipids with varying functional groups may influence differentially lutein bioavailability. Hence, the influence of glyco‐, phospho‐, neutral, crude (mixture of lipids) lipids, or mixed micelles (control) on the percent lutein micellarization in vitro and its postprandial plasma, liver, and eye response in mice were investigated. Results show that the percent micellarization of lutein with crude lipids and glycolipids were higher (91.4 and 45.7%) than control, while no significant difference was found between phospho‐ and neutral lipids. The mean plasma response of lutein was higher for crude‐ (6 times), glyco‐ (3 times), phospho‐ (2.7 times), and neutral (2 times) lipid than control (12.4 ± 1.18 nmol/mL 8 h?1) group. Lutein levels (pmol/g) in liver were higher in crude (7.4 ± 1) and phospho‐ (3.6 ± 0.8) lipid groups while in eyes it was higher in glyco‐ (54.0) and neutral (21.2) lipid groups than control. The influential effect of glyco‐ and phospholipids may be due to smaller micellar size (glyco‐upto 3.43 µm, phospho‐ upto 5.78 µm) than the neutral lipids (upto 66 µm). Ingestion of lutein with glycolipid or phospholipids may improve lutein bioavailability. Practical applications: The findings of the present study will be useful in nutritional and biomedical applications for feeding lutein with specific lipid combinations to achieve enhanced lutein absorption. Specifically, feeding diet/emulsion with lutein and glyco‐ and phospholipid combination may reduce the risk of macular degeneration, owing to the influential effect of these lipids on intestinal absorption of lutein.  相似文献   
8.
Journal of Materials Science: Materials in Electronics - Pseudo-capacitors are the emerging energy storage devices which forms a bridge between batteries and conventional capacitors. In the present...  相似文献   
9.
Digital watermarking is the process of hiding information into a digital signal to authenticate the contents of digital data. There are number of watermarking algorithm implemented in software and few in hardware. This paper discusses the implementation of robust invisible binary image watermarking algorithm in Field Programmable Gate Array (FPGA) and Application Specific Integrated Circuits (ASIC) using connectivity preserving criteria. The algorithm is processed in spatial domain. The algorithm is prototyped in (i) XILINX FPGA (ii) 130 nm ASIC. The algorithm is tested in Virtex-E (xcv50e-8-cs144) FPGA and implemented in an ASIC.  相似文献   
10.
G. Aruna  V. Baskaran 《Food chemistry》2010,123(2):404-409
The carotenoid levels in Indian spices of nutritional and medicinal importance were determined using high performance liquid chromatography. Lutein (L) and zeaxanthin (Z) levels (mg/100 g dry wt) in curry leaves (27.34), spearmint (18.0), green chilli (13.74), coriander leaves (9.92) and mustard seeds (1.2) were higher (2–22-fold) than mace, anise seeds, onion, fenugreek seeds and carum seeds (0.62 and 0.85) whilst their levels in cumin seeds, black pepper, green cardamom and coriander seeds were in the range of 0.32–0.47. β-Carotene (mg/100 g dry wt) was higher in coriander leaves (67.5), green chilli (9.06), curry leaves (8.95) and spearmint (7.5) than black cardamom (0.22) and coriander seeds (0.22), respectively. Neoxanthin, violaxanthin and α-carotene levels were also discussed. Spices analysed are a better source of L + Z than β-carotene (except for coriander leaves). Usage of spices as an adjuvant in food preparations also provides L + Z as antioxidants.  相似文献   
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