小封装LC OC-48光纤收发模块的设计

安捷伦HFCT-5942 2.488GB/s LC小封装光纤收发模块是符合SONET和SDH标准,管脚为2×10的短距离单模光纤收发模块。 文中给出了三种不同应用的参考设计。在这些设计中,HFCT.5942光纤收发模块与以下芯片联接     

Synthesis,Characterization, and Reactivity of Lanthanide Complexes with Bulky Silylallyl Ligands

The synthesis of new lanthanide allyl complexes of enhanced stability and solubility in saturated hydrocarbons based on silyl-substituted allyl ligands is reported. Thus the potassium salt K(CH₂CHCHSiMe₃) ( 1 ) reacts with YCl₃ in tetrahydrofuran to give the tris-allyl complex Y(CH₂CHCHSiMe₃)₃ ( 2 ), while K(CH₂CHCHSiMe₂^tBu) ( 3 ) affords Y(CH₂CHCHSiMe₂^tBu)₃(THF)_1.5 ( 4 ). Slow re-crystallization of 4 from light petroleum in the presence of tert-butylcyanide led to multiple insertion to give the sec-amido complex Y{NHC(^tBu)(CH)₃SiMe₂^tBu}₂{η₂-NHC(^tBu)CH=CHCH₂SiMe₂^tBu)CH(CHCHSiMe₂^tBu)C^tBuNH}(THF)·(CH₃CH(Me)(CH₂)₂CH₃) ( 5 ), which was crystallographically characterized. The reaction of ScCl₃(THF)₃ with two equivalents of Li{1,3-C₃H₃(SiMe₃)₂} in tetrahydrofuran gives the bis-allyl complex {1,3-C₃H₃(SiMe₃)₂}₂Sc(μ-Cl)₂Li(THF)₂ ( 6 ), while the analogous reaction of K{1,3-C₃H₃(SiMe₃)₂} ( 7 ) with either LaCl₃ or YCl₃ in tetrahydrofuran affords the bis-allyl complexes MCl{1,3-C₃H₃(SiMe₃)₂}₂(THF)_x (8, M = La, x = 1; 9, M = Y, x = 0). An attempt to prepare the similar neodymium complex gave the mono-allyl complex NdI₂{1,3-C₃H₃(SiMe₃)₂}(THF)_1.25 ( 10 ). The reactions of 8 and 9 with triisobutyl aluminum in benzene-d₆ show allyl exchange between lanthanide and aluminum. Complexes 8 , 9 , and 10 have been tested with a variety of activator systems as catalysts for the polymerization of 1,3-butadiene.     

Recovery of residual oil using the alkali/surfactant/polymer process: effect of alkali concentration

An experimental study was conducted to examine the effectiveness of sodium carbonate in alkali, surfactant and polymer combined slugs in recovering waterflood residual oil. The effects of sodium carbonate concentration on the slug viscosity, interfacial tension, and phase behavior were first examined. Core flood experiments were conducted with unfired linear Berea sandstone cores. The incremental oil recovery, oil cut, residual resistance factor, and chemical propagation were measured for each flood.A significant oil bank was formed for all combined slugs having sodium carbonate concentration ≥1 wt%. The incremental oil recovery, oil cut and the injectivity of the combined slugs greatly improved as sodium carbonate concentration was increased. The effect of sodium carbonate concentration on chemical propagation was dramatic for the synthetic surfactant; a slight delay in surfactant breakthrough and a much slower rate of surfactant propagation were observed at high sodium carbonate concentrations.The results obtained in the present study indicate that the residual oil was recovered by two mechanisms: low interfacial tension and wettability reversal. The former mechanism is dominant at sodium carbonate concentrations ≤1 wt%, whereas the latter plays an important role only at high sodium carbonate concentrations.     

Toward customer-usable all-optical networks

Although all-optical networks were being thought about almost ten years ago, until recently it would have been premature to talk about such networks as being truly usable. Now, ways of removing most of the roadblocks to practicality have come clearly into view. It is generally agreed that time-division packet switching in the form of asynchronous transfer mode (ATM) is likely to constitute the next generation of networking, both local and wide area; but what about the generation after that? While people are evolving SONET/ATM, the present Internet, and such emerging ambitions as the National Information Infrastructure (NII), in order to serve the needs anticipated for the next decade, optical fiber is being steadily installed at a rate of 700 miles per day in the United States alone. Furthermore, this resource is being extended steadily outward from the telco or cable provider backbone into customer premises, so that within the lifetime of the ATM generation, we may expect extremely rich fiber connectivity of a large number of homes and offices     

Testosterone has rewarding affective properties in male rats: Implications for the biological basis of sexual motivation.

Evidence from mammalian species, including humans, suggests that testosterone (TST) enhances motivational aspects of sexual behavior, although the mechanism by which TST exerts this effect is unknown. The hypothesis that increases in plasma TST have rewarding affective properties was examined. Acute elevations of plasma TST were induced in intact male rats by systemic administration of a recently developed testosterone-hydroxypropyl-β-cyclodextrin inclusion complex that mimics pulsatile release of the hormone. In a conditioned-place-preference paradigm, rats displayed a preference for an environment previously paired with TST administration (800 μg/kg and 1,200 μg/kg) as opposed to an environment paired with saline administration, indicating that TST has rewarding affective properties. The findings suggest that TST may enhance motivational aspects of mammalian sexual behavior by facilitating acquisition or expression of learned associations between environmental stimuli and sexual activity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Correlates of improvement in multidisciplinary treatment of chronic pain.

Although multidisciplinary pain programs have been demonstrated to be effective, the processes of improvement have yet to be clarified. Cognitive-behavioral models posit that improvement is due, in part, to changes in patient pain beliefs and coping strategies. To test the relationships between treatment outcome and changes in beliefs and coping strategies, 94 chronic pain patients (aged 21–64 yrs) completed measures of physical and psychological functioning, health care utilization, pain beliefs, and use of pain coping strategies at admission and 3 to 6 mo after inpatient pain treatment. Improved functioning and decreased health care use were associated with changes in both beliefs and cognitive coping strategies. However, changes in some coping strategies, such as exercise and use of rest, were not associated with improvement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of attention in face encoding.

Ss studied faces in a full- or a divided-attention condition and then received a recognition test that included old faces, new faces constructed by combining facial features from previously studied faces ("conjunction faces"), and partly or completely new faces. Full- but not divided attention Ss responded "old" more often to old than to conjunction faces; all Ss responded "old" to these faces more often than to partially or completely new faces. Thus it is less attentionally demanding to encode facial features than it is to encode their interrelations. Dividing attention had identical effects on an incidental and an intentional learning group. Exp 3 demonstrated that dividing attention primarily affected explicit recollection rather than stimulus familiarity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)