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1.
SISAK(Short-lived Isotopes Studies by the AKUFVE technique)技术是目前使用最广泛的快速化学分离方法之一,主要应用在短寿命核素的分离和鉴别、超重元素的人工合成以及化学性质研究等方面的工作中.本文简单地叙述了SISAK技术的流程、原理和发展现状,介绍了自行建立的国内第一套基于SISAK技术的快速化学分离装置,并通过从裂变产物中分离短寿命核素这一实例验证了SISAK技术在快速化学分离中的优越性.  相似文献   
2.
Poor sludge settleability is a problem encountered in many activated sludge wastewater treatment plants. This study was aimed at combatting the unwanted biological growths at the root of this phenomenon with ozone. Ozone dosed directly into the aeration basins of small activated sludge pilot plants treating both domestic and synthetic fuel wastewaters led to a substantial reduction of the bulking problem even at dosages as low as 6 to 10 mg/L. Ozone did not interfere in the delicate nutrient removal processes and significantly enhanced effluent quality.  相似文献   
3.
Ozonation of purine and pyrimidine bases and of carbohydrates was studies in laboratory experiments. The results showed that nucleobases are much more reactive with molecular ozone in aqueous solution than carbohydrates. Second order rate constants for direct reaction of ozone on purines (adenine and guanine) and on pyrimidines (cytosine, thymine and uracil) ranged from 0.76 × 103 to 6.8 × 103 M-1s-1at 2°C. The difference of reactivity between these solutes may be attributed to their substituents. As far as carbohydrates are concerned, direct reactions of ozone are very slow k03 ? 0.1 – 0.3 M-1s-1 at 20°C, and the results indicated that free radical reactions are predominant in the degradation pathway of carbohydrates by ozone. Some ozonation by-products of monosaccharides (glucose, xylose) and disaccharides (cellobiose) also were identified in this study by means of GC/MS analyses.  相似文献   
4.
分布式虚拟现实系统简称DVR,是虚拟现实系统的一种类型,它是基于网络的虚拟环境。在这个环境中,位于不同物理环境位置的多个用户或多个虚拟环境通过网络相连接,或者多个用户同时参加一个虚拟现实环境,通过计算机与其他用户进行交互,并共享信息。在分布式虚拟现实系统中,多个q用户可通过网络对同一虚拟世界进行观察和操作,以达到协同工作的目的。简单地说是指一个支持多人实时通过网络进行交互的软件系统,每个用户在一个虚拟现实环境中,通过计算机与其它用户进行交互,并共享信息。  相似文献   
5.
王艳 《电子测试》2013,(20):125-126
《世说新语》是我国现存的第一部志人小说,自此书出世后便拥有了众多的读者,对于后世影响深远《。世说新语》一书,在元代以前,其主要接受者是社会上层的文人士大夫。而在元明清时期《,世说新语》则走出了文人的书房,其故事被改编成多种形式,在市民阶层中广泛流传。传播对象的巨大转变,使得研究其在传播学中的作用,就显得更加有意义。  相似文献   
6.
How might architectural thinking and processes shift over the next 35 years? How might the architect's role be redefined with shifting ethical values? Could the architect be viewed as less of a design professional and more of a curator engaged in the development of healthy holistic environments, catering for all of society's needs? DaeWha Kang , an architect from 2050, writes to his earlier self, critiquing the work that he undertook in independent practice and as a design director at Zaha Hadid Architects in the mid-2010s. He describes how his design methodologies have evolved in the intervening years.  相似文献   
7.
A Total Diet Study (TDS) consists of selecting, collecting and analysing commonly consumed foods to obtain concentration data of different chemical compounds in foods as eaten. A TDS food list summarises the most consumed foods and represents the dietary habits of the general population of the country under study. The work reported here investigated whether TDS food lists that were initially designed for the whole population of the country under study also sufficiently cover the dietary pattern of specific subpopulations that are extra vulnerable for certain contaminants. The work was performed using data of three European countries: the Czech Republic, France and the UK. Each national food consumption database was combined with the corresponding national TDS food list (containing 336, 212 and 119 food items for the Czech Republic, France and the UK, respectively). The data were aggregated on the highest level of hierarchy of FoodEx-1, a pan-European food classification system, including 20 main FoodEx-1 groups. For the group ‘milk and dairy products’, the coverage of the consumption by the food list was investigated for more refined subgroups. For each food group or subgroup and country, the average percentage of coverage of the diet by the national TDS food list was calculated for different subpopulations, including children versus adults, women versus men, vegetarians versus non-vegetarians, and women of child-bearing age versus older women. The average diet of the different subpopulations was sufficiently covered by the food list of the Czech Republic and France. For the UK the average coverage was low due to a different food-coding approach and because food lists were not derived directly from national food consumption data. At the level of the 20 main food groups, differences between the subpopulations with respect to the average coverage of consumption by the TDS food list were minimal. The differences were more pronounced when looking in detail at the coverage of the dairy consumption. TDS food lists based on the mean consumption of the general population are also applicable to study the chemical exposure of different subpopulations, e.g. children, women of child-bearing age and vegetarians. This lowers the effort when performing a TDS.  相似文献   
8.
上海环球金融中心结构设计简析   总被引:1,自引:0,他引:1  
上海环球金融中心是一座多功能、先进智能型的摩天大厦,建成后总高度达492米,为世界第一高楼。设计建造这一超级摩天大厦是一项复杂的系统工程,尤其在结构设计方面,如何选用最有效的结构体系,如何建立完善的计算模型,以及如何进行全面的计算分析都是结构设计的关键问题。本对上海环球金融中心的结构设计及施工方案进行了较全面的介绍。  相似文献   
9.
王宇 《建筑与环境》2009,3(4):180-182
本文通过对《建成环境的意义——非言语表达方法》一书的解读,介绍了拉普卜特的环境行为学理论,为看待建筑问题提供一个新的视角。  相似文献   
10.
企业自备电厂运行稳定性技术研究   总被引:1,自引:0,他引:1  
企业自备电厂运行的稳定性差,事故率偏高.为提高电厂系统运行的稳定性,通过反复研究和分析,提出有效的技术改进措施,采用了新技术、新装备,达到了电厂系统运行的稳定性.  相似文献   
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