Full-field feed-forward equalizer with adaptive system optimization

We numerically investigate the combination of full-field detection and feed-forward equalizer (FFE) for adaptive chromatic dispersion compensation up to 2160 km in a 10 Gbit/s on–off keyed optical transmission system. The technique, with respect to earlier reports, incorporates several important implementation modules, including the algorithm for adaptive equalization of the gain imbalance between the two receiver chains, compensation of phase misalignment of the asymmetric Mach–Zehnder interferometer, and simplified implementation of field calculation. We also show that in addition to enabling fast adaptation and simplification of field calculation, full-field FFE exhibits enhanced tolerance to the sampling phase misalignment and reduced sampling rate when compared to the full-field implementation using a dispersive transmission line.     

Design and realization of long-period grating devices inconventional and high birefringence fibers and their novel applicationsas fiber-optic load sensors

We report the design and fabrication of long-period fiber gratings with single and cascaded structures in conventional and high birefringence (hi-bi) fibers using amplitude mask and point-by-point writing techniques. We also report a novel application of long-period gratings produced in nonhigh-birefringence fiber as fiber-optic load sensors exhibiting very high transverse strain sensitivity. Sensitivity some 800 times greater than previously reported fiber Bragg grating (FBG) sensors has been achieved     

Feasibility of pseudocontinuous arterial spin labeling at 7?T with whole-brain coverage

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We studied the feasibility of pseudocontinuous arterial spin labeling (pCASL) at 7 T.     

孩子的天然学堂

在澳大利亚,伴随着妇女就业和单亲家庭的增长,多数家庭和儿童都非常依赖于儿童看护服务,比如,社区幼儿园、幼儿中心、临时家     

Naturally Chiral Surfaces

Chiral surfaces are of growing importance as a result of their potential for use in enantioselective chemical processes. By far, the most widely used and commonly studied chiral surfaces are those prepared by templating of an achiral surface with chiral organic ligands. It is possible, however, to prepare naturally chiral surfaces by a number of means. This paper describes the various types of chiral surfaces. In addition, data are presented to suggest that naturally chiral surfaces of metals can be prepared by a process of imprinting in which chiral adsorbates induce reconstructions that create chiral kinks on metal surfaces.     

Mini Review on the Structure and Properties (Photocatalysis), and Preparation Techniques of Graphitic Carbon Nitride Nano-Based Particle,and Its Applications

Graphite carbon nitride (g-C₃N₄) is well known as one of the most promising materials for photocatalytic activities, such as CO₂ reduction and water splitting, and environmental remediation through the removal of organic pollutants. On the other hand, carbon nitride also pose outstanding properties and extensive application forecasts in the aspect of field emission properties. In this mini review, the novel structure, synthesis and preparation techniques of full-bodied g-C₃N₄-based composite and films were revealed. This mini review discussed contemporary advancement in the structure, synthesis, and diverse methods used for preparing g-C₃N₄ nanostructured materials. The present study gives an account of full knowledge of the use of the exceptional structural and properties, and the preparation techniques of graphite carbon nitride (g-C₃N₄) and its applications.     

Increased blood pressure later in life may be associated with perinatal n−3 fatty acid deficiency

Hypertension is a major risk factor for cardiovascular and cerebrovascular disease. Previous work in both animals and humans with high blood pressure has demonstrated the antihypertensive effects of n−3 polyunsaturated fatty acids (PUFA), although it is not known whether these nutrients are effective in preventing hypertension. The predominant n−3 PUFA in the mammalian nervous system, docosahexaenoic acid (DHA), is deposited into synaptic membranes at a high rate during the perinatal period, and recent observations indicate that the perinatal environment is important for the normal development of blood pressure control. This study investigated the importance of perinatal n−3 PUFA supply in the control of blood pressure in adult Sprague-Dawley rats. Pregnant rat dams were fed semisynthetic diets that were either deficient in (DEF) or supplemented with (CON) n−3 PUFA. Offspring were fed the same diets as their mothers until 9 wk; then, half of the rats from each group were crossed over to the opposite diet, creating four groups, i.e., CON-CON; CON-DEF; DEF-DEF, DEF-CON. Mean arterial blood pressures (MAP) were measured directly, at 33 wk of age, by cannulation of the femoral artery. The phospholipid fatty acid profile of the hypothalamic region was determined by capillary gas-liquid chromatography. The tissue phospholipid fatty acid profile reflected the diet that the rats were consuming at the time of testing. Both groups receiving DEF after 9 wk of age (i.e., DEF-DEF and CON-DEF) had similar profiles with a reduction in DHA levels of 30%, compared with rats receiving CON (i.e., CON-CON and DEF-CON). DEF-DEF rats had significantly raised MAP compared with all other groups, with differences as great as 17 mm Hg. DEF-CON rats had raised MAP compared with CON-CON rats, and DEF-DEF rats had higher MAP than CON-DEF rats, despite the fact that their respective fatty acid profiles were not different. These findings indicate that inadequate levels of DHA in the perinatal period are associated with altered blood pressure control in later life. The way in which these long-term effects are produced remains to be elucidated.     

Relationships betweenDendroctonus micans Kug. (Coleoptera: Scolytidae) survival and development and biochemical changes in Norway Spruce,Picea abies (L.) Karst., phloem caused by mechanical wounding

The bark of Norway spruce trees,Picea abies (L.) Karst., was wounded to produce areas of bark with differing biochemical characteristics. Adults and larvae ofDendroctonus micans Kug. were inserted into these trees at points around the wounds. Larval survival was higher, larval dry weights were higher, and adults were more likely to oviposit at sites around the wound that had higher phloem moisture contents. Larvae showed higher survival and dry weights in phloem with low terpene contents. Adults oviposited in phloem with lower stilbene glucoside contents. Phloem moisture differed at sites around the wound compared with that at a control site away from the wound, and the nitrogen content of entire bark cores was higher above wounds than at control sites away from the wounds. Phloem moisture correlated with the nitrogen content of entire bark. Phloem terpene contents correlated with each other, as did the stilbene contents. Associations between the host exploitation pattern ofD. micans and the biochemistry of the host phloem are discussed in relation to preselection by adults of sites suitable for larval development.