Low-power digital radio as a ubiquitous subscriber loop

The recent growth in the use of digital radio is reviewed. The technology used to implement low-power digital radio in the local exchange loop plant is discussed. The integration of digital radio subscriber loops withnetwork intelligence is explored. The relationship between low-power digital radio loops and broadband fiber loops is briefly examined, and standards and frequency allocation activities are summarized     

辽宁省城镇居民生活用水定额

本文分析了城镇居民生活用水的特点,介绍了辽宁省城镇居民生活用水定额制定的原则、方法。通过对全省县级以上城镇居民生活用水情况的调查,制定适合辽宁省实际情况的城镇居民生活用水定额。     

影响钢铁工业主要环境因素及其控制措施

针对钢铁工业的环境因素的影响 ,采取针对性措施控制 ,合理利用 ,清洁生产。     

Mechanistic investigation into the electrolytic formation of iron from iron(III) oxide in molten sodium hydroxide

Iron(III) oxide tablets were electrolytically reduced to iron in molten sodium hydroxide at 530 °C and recovered to produce iron with 2 wt.% oxygen suitable for re-melting. The cell was operated at 1.7 V and an inert nickel anode was used. The thermodynamics and mechanism of the process was also investigated. By controlling the activity of sodium oxide in the melt, the cell could be operated below the decomposition voltage of the electrolyte with the net sequence of events being the ionization of oxygen, its subsequent transport to the anode and discharge leaving behind iron at the cathode. A reduction time of 1 h was achieved for a 1 g oxide tablet (close to the theoretical reduction time predicted by Faraday’s laws) at a current density of 520 mA cm⁻² with iron phase yields of ∼90 wt.%. The energy consumption was 2.8 kWh kg⁻¹.     

New Product Development and Product Supply within a Network Setting: The Chilled Ready-meal Industry in the UK

This paper analyses inter-organizational networks that link together firms operating in the food processing and distribution industry in the UK. In doing so, the paper draws on insights recently developed by Mark Casson that treat inter-firm networks as an institutional response to the changing costs and opportunities of information management. Detailed analysis of product innovation and supply-chain management issues within the industry, exemplified by the growth of chilled ready-meals, leads to the identification of two distinct but complementary inter-firm networks: a network of control and a network of innovation. In each case, the study finds that the critical information is derived from the retailers' interface with consumers and thus that these information-based networks are effectively controlled by the leading supermarket chains. The study's conclusions are considered in relation to the recent findings of the UK Competition Commission following its investigation into grocery retailing in Britain.     

Some applications of ultraviolet spectrophotometry in drying oil research

Conclusions An alkaline-solution technique has been developed permitting the study of the drying and aging process of an oil film using the ultraviolet spectrophotometer. This technique has been found to be a valuable tool for investigating some of the chemical changes which occur as a vegetable oil film dries and ages. The drying or autoxidation of an oil film has been shown to proceed along the general lines of a three-stage reaction with the short initial stage being characterized by an accumulation of conjugated diene and triene structures which reaches a maximum at the time the film has set up or becomes continuous. The second or curing stage was characterized by a slow decrease in the measurable conjugated diene and triene structures. The third or deterioration stage was not investigated; however, this method should be readily adaptable to studies involving film breakdown as represented by phenomena such as after-yellowing since the development of absorption peaks characteristic of linolenic ketones, for example, would permit an early prediction of yellowing long before the concentration of the chromophore groups became great enough for visual observation. During the initial stage of drying there was also evidence for an increase in the alpha-keto structures capable of enolizing in alkali to give absorption maxima characteristic of triene and tetraene conjugated systems. These enolizable structures also decreased in amount during the film curing period and are not characterizable on the basis of observed absorption maxima and published information. The method of obtaining a spectral solution of a dry, infusible oil film through the medium of alcoholic KOH was applied to investigations on the relationship existing between the light absorption of the film solution and the durability or weather resistance of the straight oil film. The results obtained verified the principle previously reported that the quantity of light absorbed by an oil film in the region of 320–400 mμ was indicative of the durability of the film upon exposure to accelerated weathering conditions.     

Surgery for primary hyperparathyroidism 1962-1996: indications and outcomes

Twenty-two cases of ameloblastoma and ten cases of adenomatoid odontogenic tumour (AOT) were analyzed comparatively by the AgNOR technique. Ameloblastomas were distributed into three groups according to their clinical behaviour: primary lesions without recurrences (PLWTR), 5 cases; primary lesions with recurrences (PLWR), 4 cases; and recurrences, 13 cases. The cases were also regrouped according to their histological pattern: follicular (9 cases), plexiform (7 cases), acanthomatous (4 cases) and unicystic (2 cases). Considering histological patterns, there was a significant statistical difference only between follicular and plexiform types. There were no significant differences between the group of ameloblastomas and the group of AOTs or between the three groups of ameloblastomas with different clinical behaviour. Our results strongly suggest that the distinct clinical behaviour of ameloblastomas and AOT is not correlated with their cellular proliferation ratio. Thus, the infiltrative ability of the ameloblastomas is probably not related to the cellular proliferation index of these tumours.     

Improved alcohol-fixed smears of fine-needle aspirates for cytology of breast and other palpable lesions

The application of fine-needle aspiration cytology for the diagnosis of solid lesions is well-established. Its sensitivity as a diagnostic tool for both benign and malignant lesions can vary significantly, however, and depends on the quality of the smears submitted. In particular, air-drying artifact can render wet alcohol-fixed smears unsatisfactory for diagnosis. This study examines the basic cause of air-drying artifacts, which is directly related to the moisture of the aspirate that varies among tissues and specimens from any tumor type. A simple modification to the standard smearing technique incorporating precoated slides that introduces moisture into the aspirate is recommended. The technique is applicable to aspirates from all sites without compromising accepted diagnostic cytologic criteria, and offers excellent cytologic clarity with routine stains as well as being flexible enough for other investigative staining methods.