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951.
强化生物除磷系统的微生物种群及其表征技术   总被引:9,自引:0,他引:9  
详细介绍了强化生物除磷系统(enhanced biological phosphate removal,简称EBPR)中的微生物种群及其表征技术,提出了研究EBPR中微生物种群及其表征技术的发展方向。  相似文献   
952.
光亲和标记技术在药物发现中的应用   总被引:2,自引:0,他引:2  
功能蛋白质组学的研究在药物发现中扮演着重要的角色,而光亲和标记技术是研究功能蛋白质组学的主要策略之一,它主要有两个方面的应用:靶标蛋白的确定和活性小分子配体与靶标蛋白作用模式的揭示,这些信息为药物的发现提供了强有力的支持。  相似文献   
953.
分子生物学是生命科学的重要分支学科,目前以生物大分子为研究对象的分子生物学已经成为现代生物学领域里最具活力的学科.对分子生物学的研究内容、特点及现代分子生物技术的一些进展进行了综述,并展望了现代分子生物学的发展趋势.  相似文献   
954.
噬菌体抗体是继多克隆抗体、单克隆抗体之后兴起的第3代基因工程抗体.噬菌体抗体库技术是抗体基因文库技术和噬菌体表面展示技术相结合形成的一项新技术与方法,在生物科学领域极具潜力.现主要就近年来该技术在抗体基因扩增、抗体库的构建、筛选方法等方面的进展进行综述.  相似文献   
955.
In ‘Hard’ science, scientists correctly operate as the ‘guardians of certainty,’ using hypothesis testing formulations and value judgements about error rates and time discounting that make classical inferential methods appropriate. But these methods can neither generate most of the inputs needed by decision makers in their time frame, nor generate them in a form that allows them to be integrated into the decision in an analytically coherent and transparent way. The need for transparent accountability in public decision making under uncertainty and value conflict means the analytical coherence provided by the stochastic Bayesian decision analytic approach, drawing on the outputs of Bayesian science, is needed. If scientific researchers are to play the rôle they should be playing in informing value-based decision making, they need to see themselves also as ‘guardians of uncertainty,’ ensuring that the best possible current posterior distributions on relevant parameters are made available for decision making, irrespective of the state of the certainty-seeking research. The paper distinguishes the actors employing different technologies in terms of the focus of the technology (knowledge, values, choice); the ‘home base’ mode of their activity on the cognitive continuum of varying analysis-to-intuition ratios; and the underlying value judgements of the activity (especially error loss functions and time discount rates). Those who propose any principle of decision making other than the banal ‘Best Principle,’ including the ‘Precautionary Principle,’ are properly interpreted as advocates seeking to have their own value judgements and preferences regarding mode location apply. The task for accountable decision makers, and their supporting technologists, is to determine the best course of action under the universal conditions of uncertainty and value difference/conflict.  相似文献   
956.
海洋野生鱼与养殖鱼比较, 其鱼油中含更多的二十碳五烯酸(EPA)、二十二碳六烯酸(DHA)、脂溶性维生素等活性成分。为提高海洋野生鱼的利用价值, 以野生小带鱼为原料进行酶法提油工艺研究。分析了不同的温度, 时间, pH值等影响因素下的提取、萃取以及离心效果, 以响应面法确定了最佳的酶解工艺条件: 液固比为6、pH7.3、酶量1000 u/g原料、搅拌速度200 r/min、45oC酶解90 min; 最优萃取条件: 萃取剂100 mL(每20 g鱼糜原料)、pH4.0、40oC萃取25 min; 离心条件: 离心速度3000 r/min (1865 g)、离心时间10 min。上述工艺条件下提油率为79.90%。改进了传统的鱼油提取工艺, 在活性成分保护上有较大改善。  相似文献   
957.
Pigeons were trained in a concurrent chains procedure in which the terminal-link schedules in each session were either fixed-interval (FI) 10s FI 20s or FI 20s FI 10s, as determined by a pseudorandom binary series. The initial-link was a variable-interval (VI) 10-s schedule. Training continued until initial-link response allocation stabilized about midway through each session and was sensitive to the terminal-link immediacy ratio in that session. The initial-link schedule was then varied across sessions between VI 0.01 s and VI 30s according to an ascending and descending sequence. Initial-link response allocation was a bitonic function over the full range of durations. Preference for the FI 10-s terminal-link at first increased as programmed initial-link duration varied from 0.01 to 7.5s, and then decreased as initial-link duration increased to 30s. The bitonic function poses a potential challenge for existing models for steady-state choice, such as delay-reduction theory (DRT) [Fantino, E., 1969. Choice and rate of reinforcement. J. Exp. Anal. Behav. 12, 723-730], which predict a monotonic function. However, an extension of Grace and McLean's [Grace, R.C., McLean, A.P., 2006. Rapid acquisition in concurrent chains: evidence for a decision model. J. Exp. Anal. Behav. 85, 181-202] decision model predicted the bitonic function, and may ultimately provide an integrated account of choice in concurrent chains under both steady-state and dynamic conditions.  相似文献   
958.
The aim of the present study was to investigate the digestibility, growth and slaughter quality in Atlantic salmon (Salmo salar L.) fed a novel type of moist feed. The moist feed was prepared from alkaline preserved (pH 11.2) herring (Clupea harengus) filleting by-products, mixed with a crude binder based on seaweed before the feed was shaped in a pelleting process and the final structure was set immersing the pellets in an acidic bath. The feeding experiment was carried out with seawater-adapted salmon with an average initial weight of 1.7 kg. The moist feed and a control feed were fed to three groups of salmon with 190 fish per group. The coefficient of total tract apparent digestibility of fat, protein and energy in fish fed the moist feed was 0.96, 0.81 and 0.87, respectively. The weight gain for fish fed moist feed was significantly higher compared to salmon fed commercially extruded control feed. Carcass quality data showed that fish fed the moist feed had significantly higher dressing out percentage and less visceral fat compared to fish fed the control feed. It is concluded that alkaline preserved fish by-products can be efficiently utilized in a novel moist feed technology, yielding good growth and digestibility in Atlantic salmon.  相似文献   
959.
影响松毛虫种群动态的因素   总被引:3,自引:0,他引:3  
韩瑞东  何忠  戈峰 《昆虫知识》2004,41(6):504-511
综述了影响松毛虫种群动态的因素。气候、天敌、食料、林业技术措施等都不同程度地影响着松毛虫种群的变动。当气候条件适宜 ,天敌数量减少 ,食料丰富 ,林业技术措施缺乏时 ,松毛虫种群就会出现暴发的趋势。反之 ,当气候条件恶劣、天敌数量较多 ,食料植物缺乏或营养恶化 ,林业技术措施得当时 ,松毛虫种群就会得到遏制。尽管松毛虫的种群变动受到多种因素影响 ,但是对松毛虫自身调节能力的研究尚缺乏。  相似文献   
960.
The purpose of this research was to explore the possibility of employing PAT for particle sizing during spray drying with the use of an in-line and at-line laser diffraction system. Microspheres were made using maltodextrin and modified starch as wall material and size results obtained using PAT compared with those determined with off-line laser diffraction and light microscopy. Median particle size results were highest for in-line laser diffraction, followed by at-line and off-line laser diffraction and finally light microscopy. This was due to the presence of agglomerates which were measured as discrete microspheres in the in-line set-up. At-line and off-line laser diffraction gave results more closely correlated with individual microsphere sizes due to agglomerate breakdown during the measurement process. Light microscopy allowed direct observation of the particle morphology, however, its use for particle sizing was tedious and sample size was much smaller compared to laser diffraction. Although PAT was found to be an efficient and convenient tool, careful data interpretation was needed taking into account the cohesiveness of the material measured. The at-line set-up appeared to be more suitable in this particular application.  相似文献   
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