Bellaso's Reciprocal Ciphers

Abstract

A tableau with reciprocal alphabets used with a long keyword is commonly attributed to Della Porta. This cipher had actually been published a decade before by Giovan Battista Bellaso in a rare booklet containing other original ciphers.     

Structural and magnetic properties of nano-sized Cu-Cr ferrites prepared through a simple method using egg white

CuFe_2 − xCr_xO₄ (0 ≤ x ≤ 1) nanopowders were successfully synthesized by a simple method using metal nitrates and freshly extracted egg white. The resultant powders annealed at 550 °C for 2 h and were investigated by X-ray diffractometer (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and vibrating sample magnetometer (VSM). The results revealed the formation of cubic spinel structure at Cr concentrations ≥ 0.2. In spite of the lattice constant is hardly changed with increasing of Cr content, the magnetic properties of Cr-substituted copper ferrite are strongly affected. The saturation magnetization, remanent magnetization, and coercive force were found to decrease monotonously with increasing of Cr content.     

Key factors in tissue engineering

Tissue engineering is an emerging biomedical form of engineering aiming at regeneration of natural tissues or creation of biological substitutes for defective or lost tissues and organs using cells of different species. It is essential for the tissue self-regeneration, for instance, to provide a space necessary for regeneration with certain materials and technologies. This article overviews such key factors required for tissue engineering.     

Optimization of preparation conditions of carboxymethyl potato starch through orthogonal experimental design

To optimize the preparation conditions of carboxymethyl potato starch (CMPS), the effects of relevant factors on viscosity (η) of 2% CMPS aqueous solution and degree of substitution (DS) were investigated. These condition parameters included etherification temperature, alkalization and etherification time, water content in the mixed solvent, ratio of liquid volume to starch mass, molar ratio of sodium hydroxide to monochloroacetic acid, and molar ratio of monochloroacetic acid to anhydroglucose unit. After individual parameter influencing η and DS was researched one by one, an orthogonal experiment of L₁₈ (2 × 3⁷) was designed to identify the main factors affecting them. In light of range analysis, the comparative importance of factors impacting η and DS was obtained, separately. Results of variance analysis showed that the most effective factor to control DS was etherification temperature, whereas the influences of all factors on η were not significant. Meanwhile, η and DS of the optimized final product were found to be 12,000 mPa.s and 0.68, respectively. In addition, the structure of CMPS was characterized by Fourier transform infrared (FTIR) spectrophotometer. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

直链饱和烃及其衍生物性质的拓扑化学研究

在分析Wiener指数W的基础上,充分考虑直链饱和烃及其衍生物的结构特征,提出了一个新的拓扑指数M,并研究了M与直链饱和烃及其衍生物的一系列物理化学性质的关系,找出了P与M的普遍关系式P=aM+bM~(1/2)+c 对于不同系列的同系物和性质,常数a,b,c的值不同。     

也谈替代定理

对文献[1]中的结论提出了质疑，补充了教材中替代定理的应用条件，从而完善了替代定理。     

Industrial energy substitution during the 1980s in the Greek economy

Factor substitution in Greek manufacturing during the 1980s is examined, using pooled data in static and dynamic translog expenditure share models. Inputs are capital, labor, electricity and non-electrical energy (liquid, solid, gas). Own-price elasticities for capital and labor are inelastic, but for electricity more elastic (−0.90). Results indicate substitutability among factors in the short run. In the long run, electricity and capital are complements, as are labor and non-electrical energy. Greek manufacturing is predicted to continue decreased consumption of liquid fuels to the year 2000, continuing the electrification begun in the 1970s.     

Synthesis of NOBIN Derivatives for Asymmetric Catalysis

This account highlighted the recent advances of our research on the synthesis of enantiopure 2-amino-2′-hydroxy-1,1′-binaphthyl (NOBIN) and its derivatives as well as their applications in asymmetric catalysis, including diethyl zinc addition to aldehydes, allylic addition to aldehydes, allylic substitutions, and hetero-Diels–Alder reactions.     

Cryo preparation of isolated rabbit pancreatic islets

A Flotronic silver membrane has been used as a vehicle to process, via freeze substitution, collagenase-derived rabbit pancreatic islets. The procedure provides: (1) a simple, inexpensive method for handling larger numbers of tightly clustered islet aggregates; (2) a metal surface for rapid heat transfer from specimen to cryogen resulting in an increased circumferential zone of fine structural preservation; (3) the elimination of possible artifacts associated with impact or rotation of biological specimens against a cooled, highly polished metal block; (4) superior preservation of structural components not usually observed by conventional modes of fixation; (5) retention of metabolic components which may subsequently be available for immunocytochemical or X-ray energy dispersive procedures.     

Improved Near-Infrared Spectral Responsivity Scale

A cryogenic radiometer-based system was constructed at the National Institute of Standards and Technology for absolute radiometric measurements to improve detector spectral power responsivity scales in the wavelength range from 900 nm to 1800 nm. In addition to the liquid-helium-cooled cryogenic radiometer, the system consists of a 100 W quartz-tungsten-halogen lamp light source and a 1 m single-grating monochromator for wavelength selection. The system was characterized and the uncertainty in spectral power responsivity measurements evaluated. A variety of photodetectors, including indium gallium arsenide photodiodes (InGaAs), germanium (Ge) photodiodes, and pyroelectric detectors, were subsequently calibrated. Over most of the spectral range, the spectral power responsivity of the photodetectors can be measured with a combined relative standard uncertainty of 0.4 % or less. This is more than a factor of two smaller than our previous capabilities, and represents a significant improvement in the near infrared (NIR) spectral power responsivity scale maintained at NIST. We discuss the characterization of the monochromator-based system and present results of photodetector spectral power responsivity calibrations.