Cyclic homology of algebras with one generator

We compute the cyclic homology of A = k[X]/X ⁿ for an arbitrary commutative ring k, and we apply this result to compute the cyclic homology of k[X]/f, when k is a field and f is an arbitrary polynomial.This work was presented at the IX-ELAM, Santigo de Chile, July 1988, and was partially supported by CONICET.The following pepole participated in this research: Jorge A. Guccione, juan José guccione, Maria Julia Redondo, Andrea Solotar, and Orlando E. Villamayor.     

An evaluation of methods for contact angle measurement

A systematic comparison of Wilhelmy-balance tensiometry (WBT), tilting-plate goniometry (TPG) and captive-drop goniometry (CDG), using a variety of silane-treated glass surfaces of variable wetting characteristics is reported. WBT was assumed to be the benchmark of comparison (gold standard). Advancing angles measured by TPG and CDG were in statistical agreement with corresponding WBT measurements. In contrast, receding angles from both goniometric techniques were systematically higher than WBT.     

Effects of ocean thermocline variability on noncoherent underwater acoustic communications

The performance of acoustic modems in the ocean is strongly affected by the ocean environment. A storm can drive up the ambient noise levels, eliminate a thermocline by wind mixing, and whip up violent waves and thereby break up the acoustic mirror formed by the ocean surface. The combined effects of these and other processes on modem performance are not well understood. The authors have been conducting experiments to study these environmental effects on various modulation schemes. Here the focus is on the role of the thermocline on a widely used modulation scheme (frequency-shift keying). Using data from a recent experiment conducted in 100-m-deep water off the coast of Kauai, HI, frequency-shift-key modulation performance is shown to be strongly affected by diurnal cycles in the thermocline. There is dramatic variation in performance (measured by bit error rates) between receivers in the surface duct and receivers in the thermocline. To interpret the performance variations in a quantitative way, a precise metric is introduced based on a signal-to-interference-noise ratio that encompasses both the ambient noise and intersymbol interference. Further, it will be shown that differences in the fading statistics for receivers in and out of the thermocline explain the differences in modem performance.     

快速溶解法在测定硅铁及其合金元素中的应用

建立快速溶解硅铁及其合金的试验方法,并利用电感耦合等离子体发射光谱仪分析检测硅铁及其合金中微量元素及痕量元素,证明了快速溶解法的可行性.结果显示,方法的精密度及检测仪器重复性测量不确定度的结果均符合国家标准规定的允许偏差范围,说明快速溶解法具有一定推广价值和应用前景.     

Synthesis and Structure of Inclusion Complex of Cyclomaltoheptaose（β—Cyclodextrin）with m—Aminophenol

ＩｎｔｒｏｄｕｃｔｉｏｎＳｕｐｒａｍｏｌｅｃｕｌｅｉｓａｋｉｎｄｏｆｓｙｓｔｅｍｗｉｔｈｓｐｅｃｉａｌｓｔｒｕｃ ｔｕｒｅｄｅｐｅｎｄｉｎｇｏｎｔｈｅｗｅａｋｍｏｌｅｃｕｌａｒｉｎｔｅｒａｃｔｉｏｎｓ (ｓｕｃｈａｓｖａｎｄｅｒＷａａｌｓ ,ｈｙｄｒｏｇｅｎｂｏｎｄ ,ｅｌｅｃｔｒｏｓｔａｔｉｃａｎｄｈｙ ｄｒｏｐｈｏｂｉｃｉｎｔｅｒａｃｔｉｏｎｓ) .Ｔｈｅｗｅａｋｉｎｔｅｒａｃｔｉｏｎｓａｒｅｒｅｌａｔｅｄｔｏｂｉｏｌｏｇｉｃａｌｐｒｏｃｅｓｓｅｓ ,ｆｏｒｅｘａｍｐｌｅ ,ｔｈｅｃａｔａｌｙｔｉｃｒｅａ…     

Hydrothermal Synthesis and Structural Characterization of the Cage-based Arsenic-Vanadium Microporous Material: [As_2V~(IV)_8V~V_2O_(26)]·8H_2O

Interest in polyoxometalates is expanding rapidly due to the enormous variety of structure topologies leading to interesting and unexpected properties in such diverse field as catalysis, materials science and medicine1-4. Frameworks constructed from square pyramidal, octahedral, tetrahedral units are well documented in the solid-state phases of the V/O/P system5. For the heteropolyanions class of clusters, the V/O/As system has been extensively studied, but the linking of arsenic-vanadium …