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91.
红外分光光度法测定水中油类物质吸附方法的比较   总被引:1,自引:0,他引:1       下载免费PDF全文
吸附处理是红外法测定石油类的一个重要环节.通过实验对吸附柱法和振荡吸附法进行对较,结果表明动植物油质量浓度为0.560 mg/L~145 mg/L的水样,振荡吸附法吸附效率高于吸附柱法.振荡吸附法还具有操作时间短、硅酸镁耗量低、对操作人员危害性小、样品可批量分析的优点.  相似文献   
92.
The concept of natural behavior is a key element in current Dutch policy-making on animal welfare. It emphasizes that animals need positive experiences, in addition to minimized suffering. This paper interprets the concept of natural behavior in the context of the scientific framework for welfare assessment. Natural behavior may be defined as behavior that animals have a tendency to exhibit under natural conditions, because these behaviors are pleasurable and promote biological functioning. Animal welfare is the quality of life as perceived by the animal. Animals have evolved cognitive-emotional systems (“welfare needs”) to deal with a variable environment. Animals do not only have so-called physiological needs such as the need for food, water, and thermal comfort. They also need to exercise certain natural behaviors such as rooting or nest-building in pigs, and scratching or dust-bathing in poultry. All needs must be taken into account in order to assess overall welfare. The degree of need satisfaction and frustration can be assessed from scientific information about the intensity, duration, and incidence of (welfare) performance criteria such as measurements of behavior and/or (patho)physiology. Positive welfare value relates to how animals are inclined to behave under natural conditions, in preference tests, and in consumer-demand studies. Negative welfare value relates to stress, frustration, abnormal behavior, aggression, and reduced fitness. Examples are given to illustrate how the need to perform natural behaviors can be assessed following the general principles for welfare assessment, providing a first approximation of how different natural behaviors affect animal welfare.  相似文献   
93.
In common with much of theEnglish-speaking world, New Zealandersgenerally oppose the use of animalexperimentation where there is no demonstrableand immediate benefit for human, animal, orenvironmental health. Intrusive experiments onsheep internal and external parasites publishedbetween 1996 and 2000 are reviewed, anddiscussed in relation to these publicsensibilities. A total of 16 publishedexperiments on sheep parasites involvedsurgical manipulations or other intrusiveprocedures. Some of these experiments had noshort-term application, or the only applicationwas in increasing animal production. Otherscould have been modified at some extra expenseso that they were less intrusive. Still otherswere duplications of previous work. All thesemanipulations would be unacceptable accordingto the orthodox morality of the general public.Breeding programs, rotation of grazing,``low-tech' vaccination, and in vitromodels of sheep can provide insights intopreventing parasite infestation withoutintrusive experiments. Such research protocolsshould take priority over existing programs.The results also confirm earlier reports thatanimal ethics committees are not fulfillingtheir mandated objective of acting as watchdogsfor the public. Possible changes in New Zealandanimal welfare legislation and itsinterpretation by Animal Ethics Committees arediscussed.  相似文献   
94.
Energy use scenario and resulting rice yield of 576 farms belonging to six agroclimatic zones of Assam, India were investigated. Input energy from eight distinct sources, viz., human, animal, diesel, commercial chemical fertilizer, farm yard manure (FYM), seed, pesticide chemical and machinery were determined on the basis of collected data and using standard procedure. Based on the power sources used and application of commercial chemical fertilizer, four categories of farms were delineated: (i) animal power without commercial fertilizer (APNF), (ii) animal power with commercial fertilizer (APF), (iii) mechanical power without commercial fertilizer (MPNF) and (iv) mechanical power with commercial fertilizer (MPF). The best-fit curve of energy versus yield indicated that use of commercial chemical fertilizer and mechanical power resulted in higher rice yield at higher level of input energy. Moreover, as the use of energy increased the yield increased up to maxima and then declined at higher levels of energy. This was observed in all four categories of farms with variation in yield–energy values. The average values of energy input (MJ ha−1) and corresponding yield (kg ha−1) for the APNF, APF, MPNF and MPF type of farms were (5220, 1980); (9050, 3170); (5100, 2360) and (8320, 3800), respectively. Renewable energy dominated the rice cultivation in Assam contributing more than 50% of the total input energy with the exception of MPF category of farm where share of renewable and non-renewable were found to be almost equal. Among the farm operations, tillage was the highest energy consuming operation followed by threshing, harvesting and transplanting for all four categories of farms. However, it was observed that rice yield was not positively correlated with tillage energy.  相似文献   
95.
本文叙述了我国家养动物多样性的现状以及畜牧业发展中家养动物多样性保护与利用的目标及其效益;提出当前我国家养动物保扩和利用面临的问题;并就家养动物多样性保护和利用提出了7个方面的措施,强调家养动物多样性是促进畜牧业持续发展的前提。  相似文献   
96.
The process by which ant scouts move a group of nestmates toward a newly discovered food site is called recruitment. In this paper, I report on the interactions between scouts and nestmates that result in a graded recruitment response to graded food quality in the fire ant, Solenopsis invicta. Twelve experimental groups composed of 100 fire ant workers and 50 fire ant larvae were established (three experimental groups per colony × four stock colonies). Each experimental group was placed in a shallow, artificial nest with a glass cover. After a 48-h period of food deprivation, experimental groups were exposed to one of three concentrations of sugar water. Behavioral interactions between scouts and nestmates in each group were videotaped at 10× magnification for 20 min. Detailed behavioral data on a total of 120 scouts (10 scouts per experimental group) and ~1,000 nestmates (~90 nestmates per experimental group) were transcribed from the videotapes using standard play and frame-by-frame techniques. Throughout the recruitment process, scouts employed six discrete behaviors to inform nestmates of the location and quality of a food site. Scouts laid incoming trails, waggled their heads, increased walking tempo, stroked nestmates with their antennae, advertised with a brief food display, and led groups of nestmates to the food site by laying outgoing trails. In turn, nestmates assessed the food sample with antennae, then responded to or resisted recruitment based on the quality of food advertised, their employment status and their level of hunger. In summary, recruitment was an emergent property based on competent supply and demand decisions made face-to-face inside the nest rather than on the trail or at the food site.Communicated by J. Heinze  相似文献   
97.
The association between spatial proximity and paternity was studied in a population of the striped plateau lizard, Sceloporus virgatus. The relationship between estimated mating success and male phenotypic traits was examined for a sample of 55 males. DNA samples were obtained from 13 female-offspring families. The males with the closest spatial proximity to each female were tested as possible sires within each family. Fingerprinting with two multilocus hypervariable minisatellite probes revealed a strong correspondence between male-female spatial proximity and actual paternity. Paternity could be assigned for 72 of the 100 hatchlings. Most hatchlings with identifiable sires were attributed to a male with the highest category of spatial proximity to the mother. However, there was a low to moderate level of multiple paternity within clutches, and for some clutches probable sires could not be identified even though the most likely behavioural candidates were tested. Thus, nonterritorial males or other males lacking strong social and spatial relationships with females may achieve some degree of reproductive success. Analysis of mating success revealed that male success increased with body size, up to a point beyond which larger size conferred no advantage. Received: 7 January 1997 / Accepted after revision: 16 June 1997  相似文献   
98.
Prairie dogs (Cynomys spp.) have been poisoned throughout this century because of grazing competition with livestock. Recent evidence showed these early claims were exaggerated, but animal control was already entrenched in government policy. As a result, ongoing government subsidized poisoning has reduced prairie dogs to about 2% of their former distribution. The reduction of prairie dogs diminished species diversity in the arid grasslands of North America, including the potential extinction of the black-footed ferret (Mustela nigripes). Cost-benefit analysis revealed that poisoning costs more than any grazing benefits accrued. This analysis did not consider the long-term costs of reversing ecosystem degradation, the intangible value of biological diversity as a public benefit, or the depletion of biotic resources as a loss of actual or potential wealth. The government presently finances the poisoning policy and the preservation of endangered species like the black-footed ferret, two apparently conflicting programs. We, therefore, propose an integrated management plan that considers both interests. We propose that federal monies allocated to the poisoning program be converted into a rebate for ranchers who manage livestock while preserving the prairie dog community. This would redirect funds and personnel already allocated to prairie dog eradication to an incentive for ranchers who manage for livestock and wildlife. Livestock interests and grassland biotic diversity would both benefit.  相似文献   
99.
畜粪污染处理与利用研究   总被引:4,自引:0,他引:4  
国内外对于粪便固体物的处理主要采用焚烧法、干燥法和堆肥法等,在粪便污水处理方面主要采用厌氧消化法,它将治污、产气和综合利用相结合,使废物资源化,达到环境效益、经济效益和社会效益相统一。  相似文献   
100.
自配动植物油的四氯化碳溶液.用红外分光光度法进行测定,测定浓度小于配制浓度.测定浓度与配制浓度线性相关性良好.测得相关性方程.在水样测定时,将测定值作为信号值代入线性方程,对测定值进行校正,校正后所得结果更加符合动植物油的实际浓度.  相似文献   
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