基于CIP现场总线的风力送丝控制系统设计

以卷烟厂制丝线的风力送丝系统为对象,研究了DeviceNet和ControlNet这2种CIP现场总线在工程上的实际应用.在项目的开发和设计中,采用了上层ControlNet和底层DeviceNet的2层网络模式,并结合了网络的配置,从而完成了PLC控制程序和触摸屏程序的设计.     

松材线虫和拟松材线虫的繁殖力及其超氧自由基差异

采用不同毒力的松材线虫和拟松材线虫进行研究,探讨不同毒力线虫的繁殖力及虫体自身超氧自由基(O·2)释放能力差异与各虫株致病力之间的关系。对强、弱毒松材线虫和无毒拟松材线虫在单异活体培养下的繁殖力进行测定,发现三者的繁殖力从大到小依次为：无毒拟松材线虫、强毒松材线虫、弱毒松材线虫。单异活体培养下的松材线虫和拟松材线虫虫体、水培滤液的超氧自由基测定表明,两组分中的超氧自由基含量与供试线虫的毒力呈负相关,从高到低依次为：无毒拟松材线虫、弱毒松材线虫、强毒松材线虫。结果表明：供试的不同毒力松材线虫和拟松材线虫的致病力与其繁殖力无显著相关性,但与其虫体超氧自由基含量有密切关系。     

Terrapotamon gen. nov., a new genus of freshwater crabs from Malaysia and Thailand,with description of a new species,Terrapotamon aipooae sp. nov. (Crustacea: Decapoda: Brachyura: Potamidae)

A new genus, Terrapotamon gen. nov., is established to accomodate two species of freshwater crabs, Potamon abbotti Rathbun, 1898 from southern Thailand, and a new species, Terrapotamon aipooae sp. nov. from West Malaysia. Members of this genus are characterized by their inflated carapaces, very acutely triangular external orbital angles, and structure of their first male gonopods.     

Contrasting modes of handling moss for feeding and case‐building by the caddisfly Scelotrichia willcairnsi (Insecta: Trichoptera)

Final‐instar larvae of the microcaddisfly, Scelotrichia willcairnsi sp. nov. (Trichoptera: Hydroptilidae) were discovered feeding on a moss, Platyhypnidium muelleri in north‐eastern Queensland. Not only do the larvae feed on the moss, but their cases are constructed from fragments of moss leaves. Microscopic examination of larval guts and cases showed a total contrast in the angle at which the moss leaves are cut for each purpose: for cases the moss leaves are cut longitudinally, in parallel with the length of the cells, whereas for feeding the leaves are cut perpendicular to the leaf margin, across the cells, presumably an adaptation that releases the cell contents for digestion. The new caddisfly species is described based on the adult males. Scelotrichia willcairnsi represents the first Australian record of the South‐east Asian‐New Guinean Stactobiini genus Scelotrichia.     

Do male tree frogs feed during the breeding season? Stomach flushing of five syntopic hylid species in Rio Grande do Sul,Brazil1

The diet of males of five syntopic hylid species from the Araucaria plateau of Rio Grande do Sul was studied by stomach flushing. Because the duration of their breeding seasons was rather different, the levels of food intake at the respective breeding sites were analysed. We found a positive correlation between the length of the male calling period and the ingestion of prey. The longer the species‐specific reproductive activity of the males, the more individuals fed during that time. The results are discussed under congruence aspects of feeding and mating microhabitats in these tree frogs. In addition, differences in niche breadth may influence the temporal and spatial partitioning between the species studied and result in quantitative as well as qualitative patterns of prey consumption, thereby ensuring a maximum of fitness gain.     

Patterns of species participation across multiple mixed-species flock types in a tropical forest in northeastern India

We studied mixed-species bird flocks in northeastern India to (a) develop a framework for quantifying species participation in mixed-species flocks, (b) characterize the ecology and behaviour of participant species, and (c) explore mechanisms influencing the coexistence of different mixed-species flock types. To characterize participation in mixed-species flocks, we implement a new method incorporating species abundances, minimizing potential biases in measuring participation arising from differences in the availability of flocking species. There are at least three distinct flock types in the lowland forests of northeastern India; these flock types differ in the body mass and vertical stratum use of participant species. The “core” of mixed-species flocks was composed of a species group that differed much more in their foraging method in comparison with “attendant” species. The exchange of benefits and minimization of interspecific competition might lead to, and maintain, heterogeneity in foraging methods among core species of mixed-species flocks.     

II.—Association between sessile colonial hydroids and fishes

Résumé

1. 1. There is a symbiosis between Sertularia operculata and Squalus acanthias, and between Seralia lendigera and Hippocampus ramulosus—there being but a single case reported for each pair of organisms. It is probable that these associations are entirely accidental.

2. 2. Of Stylactis minoi and Minous inermis, no fewer than twenty-nine specimens of the fish (presumably all ever taken) wherever found—and they have been taken from five widely distant stations on both coasts of India, and from Japan—were infested with the hydroid. Furthermore, so far as known, this particular hydroid has never been found save on this particular fish (inermis). These facts would seem to indicate that this is a purposive or obligate symbiosis.

3. 3. About one hundred specimens of Hypsagonus quadricornis were taken in Puget Sound. Thirty-seven of these were preserved, and ten of them were found to be sparsely covered with Perigonimus pugetensis. Other specimens of the fish taken outside Puget Sound and in Behring Sea all lacked the hydroid. Consideration of all these facts leads to the conclusion that the association is symbiotic and more or less accidental.

4. 4. One case has been presented of Hydrichthys mirus attached to Seriola zonata in Narragansett Bay. Parasitism is alleged, but the proofs offered, that there was some apparent degeneration on the part of the hydroid and some slight evidence of wasting away of the muscles of the fish at the point of attachment, are at best inconclusive, there being no evidence from sections presented to show actual anastomosis of the tissues of the two organisms. From the evidence presented one must conclude that this is only a case of symbiosis.

5. 5. One case is known of the attachment of a Nudiclava to a fish, Monacanthus, from the Andaman Sea. Parasitism is alleged in the title of the paper, but disclaimed in the text, since, in sections cut through the basal plate and the skin to which it was attached, such was not proven. Furthermore, the finding of food in the hydranths discounts the idea of parasitism. This case also must be classed as a symbiosis.

6. 6. True parasitism has been repeatedly shown to exist between an aberrant hydroid, Polypodium hydriforme, and the ovarian eggs of the Volga sterlet, Acipenser ruthenus. This has been definitely established by the work of four investigators, extending in time from 1872 to 1922—a half century. Except in its earliest stages, Polypodium has the nutritive cell-layer of its stolon, the endoderm, on the outside bathed in the egg-yolk. Later this becomes inverted and a large amount of yolk is carried into the common cavity. The egg is used up in nourishing the parasite.

7. 7. True parasitism has been shown between Hydrichthys boycei and numerous individuals of three species of fishes—Ambassis natalensis, Mugil sp., and an undetermined fish belonging to the Glyphidodontidæ—in Durban Bay, South Africa. The parasites were attached to various parts of the fishes, especially the fins. At the points of attachment, haustoria were sent down into flesh and into blood-vessels, and by means of these the parasite fed on the tissues of its host. Furthermore, on none of the hydranths were tentacles ever found, nor was any food ever found in them. Strange to say, the parasite never covers any large area of the fish, and apparently presently drops off leaving a scar behind.

     

改进型Elman网络在水厂智能投药控制系统中的应用

水厂投药系统由于存在非线性、大滞后、多输入因子等特点,多年来难以实现自动控制.在充分分析自来水厂现有的大量有效历史数据和丰富实践经验的基础上,建立了基于Elman动态神经网络的智能混凝投药控制方式,并对系统的实现作了较为详细的说明.实践证明,该系统具有自学习和自适应的能力,控制精度高,克服了传统人工操作的失误隐患,并取得了较好的经济效益.     

公平偏好下销售回扣契约供应链协调

针对传统的销售回扣契约无法实现供应链协调, 引入普遍存在的公平偏好, 探讨销售回扣契约对协调供应链的影响. 假设在市场需求是随机的两阶段供应链中的零售商具有公 平偏好, 运用公平偏好模型, 分别就零售商订货量小于销售回扣临界值和订货量大于等于销售回扣临界值这两种情形进行分析. 研究发现加入公平偏好的销售回扣契约扩展了 零售商与供应商自愿合作的前景, 能提高供应链的整体利润和效用, 得到充分合作的均衡结果, 从而更好地协调供应链. 最终使用算例验证了结论.