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排序方式: 共有446条查询结果,搜索用时 15 毫秒
1.
Daryl Letto Derek Webb Mark Rupke Brian Herner 《中国给水排水》2007,23(24):103-108
对采用天然有机滤料和合成无机滤料的生物除臭滤池在加拿大多伦多市Ash-bridge’s Bay污水厂污泥处理站的干化和转运段的应用效果进行了分析。详细介绍了污泥脱水工艺、臭气的产生及其组分,进而对软木树皮滤料和矿物合成永久性滤料的除臭效果进行了比较。还讨论了一些具体的运行经验,并采用动态模型对不同条件下的运行数据进行了分析。 相似文献
2.
SW D'Souza E Rivlin J Cadman B Richards P Buck BA Lieberman 《Canadian Metallurgical Quarterly》1997,76(2):F70-F74
AIMS: To compare the outcome in in vitro fertilisation (IVF) children (after fresh embryo transfer) from multiple and singleton births with one another, and with normally conceived control children. METHODS: A cohort of 278 children (150 singletons, 100 twins, 24 triplets and four quadruplets), conceived by IVF after three fresh embryos had been transferred, born between October 1984 and December 1991, and 278 normally conceived control children (all singletons), were followed up for four years after birth. They were assessed for neonatal conditions, minor congenital anomalies, major congenital malformations, cerebral palsy and other disabilities. Control children, all born at term, were matched for age, sex and social class. RESULTS: The ratio of male:female births was 1.03. Forty six per cent of IVF children were from multiple births; 34.9% were from preterm deliveries; and 43.2% weighed less than 2500 g at birth. The IVF singletons were on average born one week earlier than the controls, weighed 400 g less, and had a threefold greater chance of being born by caesarean section. The higher percentage of preterm deliveries was largely due to multiple births and they contributed to neonatal conditions in 45.0% of all IVF children. The types of congenital abnormalities varied: 3.6% of IVF children and 2.5% of controls had minor congenital anomalies, and 2.5% of IVF children and none of the controls had major congenital malformations. The numbers of each specific type of congenital abnormality were small and were not significantly related to multiple births. IVF children (2.1%) and 0.4% of the controls had mild/moderate disabilities. They were all from multiple births, including two children with cerebral palsy who were triplets. CONCLUSIONS: The outcome of IVF treatment leading to multiple births is less satisfactory than that in singletons because of neonatal conditions associated with preterm delivery and disabilities in later childhood. A reduction of multiple pregnancies by limiting the transfer of embryos to two instead of three remains a high priority. 相似文献
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Holden Ronald R.; Kroner Daryl G.; Fekken G. Cynthia; Popham Suzanne M. 《Canadian Metallurgical Quarterly》1992,63(2):272
Proposes and empirically evaluates a general model of faking on self-report personality test items. The model predicts that differential test item response latencies should be faster for schema-congruent test answers than for noncongruent responses. Thus, individuals faking good should take relatively longer to endorse socially undesirable test item content than desirable test item content. Conversely, individuals faking bad should endorse socially desirable test item content relatively slower than undesirable test item content. Support for the model was found to generalize across personality inventories and across populations of university students and maximum security prisoners. Conflicting results from previous research are viewed in terms of the model. Further testing of the model's generality and practical relevance is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
6.
Amplification of a 340 bp sequence of the 38 kDa protein gene of Mycobacterium tuberculosis by the polymerase chain reaction has been developed. The sensitivity of this PCR was shown to be 10 fg both by agarose gel electrophoresis and Southern blot hybridisation being equivalent to 2-3 organisms and highly specific to M. tuberculosis and excluding even M. tuberculosis H37Ra and Mycobacterium bovis BCG. Sputum samples from patients with pulmonary tuberculosis gave a positivity rate of 45%. PCR was also performed using pt8 and pt9 primers which amplified a 541 bp sequence of IS6110. 41% of the above samples gave positive amplification. Three samples that were positive for 38 kDa sequence were negative for IS6110. 相似文献
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Over the last few decades, many different evolutionary algorithms have been introduced for solving constrained optimization problems. However, due to the variability of problem characteristics, no single algorithm performs consistently over a range of problems. In this paper, instead of introducing another such algorithm, we propose an evolutionary framework that utilizes existing knowledge to make logical changes for better performance. The algorithmic aspects considered here are: the way of using search operators, dealing with feasibility, setting parameters, and refining solutions. The combined impact of such modifications is significant as has been shown by solving two sets of test problems: (i) a set of 24 test problems that were used for the CEC2006 constrained optimization competition and (ii) a second set of 36 test instances introduced for the CEC2010 constrained optimization competition. The results demonstrate that the proposed algorithm shows better performance in comparison to the state-of-the-art algorithms. 相似文献
9.
Robin R. Murphy Eric Steimle Michael Hall Michael Lindemuth David Trejo Stefan Hurlebaus Zenon Medina-Cetina Daryl Slocum 《Journal of Intelligent and Robotic Systems》2011,64(1):77-95
The Center for Robot-Assisted Search and Rescue (CRASAR®) deployed a customized AEOS man-portable unmanned surface vehicle and two commercially available underwater vehicles (the autonomous YSI EcoMapper and the tethered VideoRay) for inspection of the Rollover Pass bridge in the Bolivar peninsula of Texas in the aftermath of Hurricane Ike. A preliminary domain analysis with the vehicles identified key tasks in subsurface bridge inspection (mapping of the debris field and inspecting the bridge footings for scour), control challenges (navigation under loss of GPS, underwater obstacle avoidance, and stable positioning in high currents without GPS), possible improvements to human-robot interaction (having additional display units so that mission specialists can view and operate on imagery independently of the operator control unit, incorporating 2-way audio to allow operator and field personnel to communicate while launching or recovering the vehicle, and increased state sensing for reliability), and discussed the cooperative use of surface, underwater, and aerial vehicles. The article posits seven milestones in the development of a fully functional UMV for bridge inspection: standardize mission payloads, add health monitoring, improve teleoperation through better human-robot interaction, add 3D obstacle avoidance, improve station-keeping, handle large data sets, and support cooperative sensing. 相似文献
10.
Confocal laser scanning microscopy (CLSM) offers improved depth discrimination and spatial resolution to the analysis of biologic samples. We demonstrate in this paper that such technology is valuable in examining DNA single-strand breaks in human cells. The single-cell-gel (SCG) assay is a new technique for measuring DNA strand breaks in individual cells. Cells embedded in lowmelting-point agarose are treated with varying concentrations of hydrogen peroxide to induce DNA strand breaks. Following cell lysis and alkaline electrophoresis, which enables single-stranded break detection, analysis of the resulting “comets” provides an accurate method of comparing changes in DNA migration patterns, which have been shown to reflect the DNA damage levels. A statistically significant difference (p < 0.01) in single-stranded DNA damage levels was detected in cells exposed to hydrogen peroxide concentrations as low as 10 nm for 2 min. LSM analysis of the SCG technique allows rapid, sensitive and reproducible quantitation of single-stranded breaks of cellular DNA. 相似文献