CCD型束流截面探测器

CCD型束流截面探测器的主要特点是使用电荷耦合器件做传感器,用束流同步光中的可见光成份做为信号源。该探测器同时具有模拟量和数字量两种输出,工作周期短,速度高,不影响束团粒子寿命,在电子储存环物理运行中,是一种有效的探测设备。     

Fractoemission from Lead Zirconate-Titanate

We present measurements of the electron, positive ion, and photon emission accompanying the fracture in vacuum of poly-crystalline 95/5 lead zirconate-titanate. The intensities of the charged-particle components of this fractoemission are shown to depend strongly on the direction (relative to the direction of fracture) and magnitude of polarization. The most intense emission is observed when the fracture surfaces are perpendicular to the polarization direction. The emission intensity increases monotonically with polarization. These results are interpreted in terms of a model involving charge separation on the fracture surfaces leading to a microdischarge during fracture. Implications to the interpretation of triboluminesence effects are discussed.     

A Collection of Papers and Memoirs Celebrating the Contribution of Rod Burstall to Advances in Computer Science

Formal Aspects of Computing are dedicated to Professor Rod Burstall, and, as a collection of papers, memoirs and incidental pieces, form a Festschrift for Rod. The contributions are made by some of the many who know Rod and have been in uenced by him. The research papers included here represent some of the areas in which Rod has been active, and the editors thank their colleagues for agreeing to contribute to this Festschrift.     

PROCESSING AND QUALITY EVALUATION OF WHOLE CANNED 'DWARF' GOLDEN APPLES (SPONDIAS CYTHEREA)

‘Dwarf’ golden apples (Spondias cytherea) were canned in sucrose syrup of either 30 d?Brix (L) or 40 d?Brix (H). Processing was either by hot filling (HF) of syrup at 92C in filled cans or by steam‐exhausting (SE) of the filled cans at 85C for 12–14 min, followed by processing at 100C for 20 min (W₂₀) or 30 min (W₃₀). Sensory evaluation of commercial sterile products, SE‐LW₃₀ and SE‐LW₃₀ indicated there were no differences (P < 0.05) in appearance, color, taste, aroma and texture. Overall scores indicated that fruits in syrup were liked definitely to like slightly. Panelists indicated that they might or definitely will purchase the products. Fruits in 40 d?Brix syrup were firmer than in 30 d?Brix syrup. By week 8 of storage at 28–30C, pH was stable between 3.6–3.7, and ‘cut‐out’d?Brix of syrup for LW₃₀ and HW₃₀ products was 24.0 – 24.5 and 28.5, respectively.     

Use of a 5-caffeoylquinic Acid/Caffeine Ratio to Monitor the Coffee Roasting Process

The extent of alteration in the chemical composition of coffee beans roasted to develop the flavor and aroma associated with coffee beverage was reliably monitored by observing the decomposition of naturally occurring 5-caffeoylquinic acid (5-CQA) and ratioing this concentration to that of the relatively heat stable caffeine. An HPLC method was developed by which simultaneous quantification of 5-CQA and caffeine could be used to monitor degree of roast.     

Markets and Hierarchies and (Mathematical) Economic Theory

Over the past decade transaction-cost economics has been partiallytranslated in the more mathematical language of game theory,and understanding of the costs of transactions has been deepened,refined and extended. But the translation is incomplete: a greatdeal of human behaviour is missed, and doing game theory withmore life-like models of individuals will bring theory closerto phenomena. Transaction-cost economics, particulary the economicsof relational contracts, provides a major arena for these developments,since the important issues of bounded rationality and individualbehavior are central to the topic.     

STORAGE OF RETORT POUCH BEEFSTEAK AND BEEF STEW PACKED UNDER FOUR HEADSPACE LEVELS

Changes in specific physico-chemical and sensory attributes as well as acceptability of beefsteak and beef stew Meal-Ready-to-Eat (MRE) components packed under different headspace levels (10, 20, 30 and 40 cm³) and stored at selected temperatures of 4, 27 and 38C (40, 80 and 100F) were evaluated over a six month period. No significant changes in microbial counts, pH, residual oxygen, color, hardness and oxidation occurred in retort-packed beefsteak or beef stew. Unlike beefsteak, beef stew received acceptable scores by consumers during all six months of analysis. Consumers' lack of familiarity with beefsteak may have negatively influenced product acceptability. Beefsteak and beef stew acceptability and specific attributes, particularly moistness and firmness, were detrimentally affected by high storage temperatures. Headspace may be increased to 40 cm³ without significant detrimental effects on product quality and acceptability of beefsteak or beef stew.     

PATATIN AND ESTERASE IN DESIREE POTATO TUBERS1

Patatin, the major glycoprotein of potato tubers, had very similar chemical and physical properties whether isolated from cultivar Desiree or from Kennebec. The patatin of each cultivar exhibited copurification with p-nitrophenyl laurate esterase. However, the esterases from the two sources differed in substrate preference ranging from near equality toward α-naphthyl laurate to a hundredfold difference toward p-nitrophenyl laurate.     

BIOFUMIGANT COMPOUNDS RELEASED BY FIELD PENNYCRESS (<Emphasis Type="Italic">Thlaspi arvense</Emphasis>) SEEDMEAL

Defatted field pennycress (Thlaspi arvense L.) seedmeal was found to completely inhibit seedling germination/emergence when added to a sandy loam soil containing wheat (Triticum aestivum L.) and arugula [Eruca vesicaria (L.) Cav. subsp. sativa (Mill.) Thell.] seeds at levels of 1.0% w/w or higher. Covering the pots with Petri dishes containing the soil-seedmeal mixture decreased germination of both species at the lowest application rate (0.5% w/w), suggesting that the some of the phytotoxins were volatile. CH₂Cl₂, MeOH, and water extracts of the wetted seedmeal were bioassayed against wheat and sicklepod (Senna obtusifolia (L.) H. S. Irwin & Barneby) radicle elongation. Only the CH₂Cl₂ extract was strongly inhibitory to both species. Fractionation of the CH₂Cl₂ extract yielded two major phytotoxins, identified by gas chromatography–mass spectrometry and NMR as 2-propen-1-yl (allyl) isothiocyanate (AITC) and allyl thiocyanate (ATC), which constituted 80.9 and 18.8%, respectively, of the active fraction. When seeds of wheat, arugula and sicklepod were exposed to volatilized AITC and ATC, germination of all three species was completely inhibited by both compounds at concentrations of 5 ppm or less. In field studies, where seedmeal was applied at 0.50, 1.25, and 2.50 kg/m² and tarped with black plastic mulch, all of the treatments significantly reduced dry weight of bioassay plants compared to the tarped control, with the highest seedmeal rate decreasing dry matter to less than 10% of the control 30 d after seedmeal application. Field pennycress seedmeal appears to offer excellent potential as a biofumigant for high-value horticultural crops for both conventional and organic growers.Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also be suitable.     

Crystallization of Beta NaFeO2 from a Glass Along the Na2SiO3-Fe2O3 Join

Fine-particle beta sodium ferrite (β-NaFeO₂), rather than α-Fe₂O₃, may be responsible for superparamagnetic behavior in a glass of composition (in mole fractions) 0.37Na₂O-0.26Fe₂O₃-0.37SiO₂. The 700°C isothermal section of the phase diagram of the Na₂O-Fe₂O₃-SiO₂ system is given, showing a three-phase field bounded by Na₂SiO₃-NaFeO₂-Fe₂O₃; there is no evidence for the existence (at 700°C) of compounds of molar composition 6Na₂O-4Fe₂O₃-5SiO₂ or 2Na₂O-Fe₂O₃-SiO₂. The Moessbauer spectrum of β-NaFeO₂ has an internal magnetic field of 487 kOe at room temperature.