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41.
Conclusion The experinece of the application of the finite element method shows that this is the most efficient and convenient of the methods used at the present time for the computation of stresses in slopes and earth dams. The computer program based on this method can take into account any arbitrary geometry of the cross section, a large diversity in the loading conditions and in the porperties of the construction material and of the foundation. The results obtained so far in the practical applications indicate that the finite element method can be used with confidence for the computation of earth and rockfill dams and their foundations, both under static and dynamic loads, including seismic forces. This paper was written during Professor W. D. Liam Finn's stay in the USSR, in accordance with the scientific exchange program concluded between the Academy of Sciences of the USSR and the Canadian Research Council. Part of the investigations described in this paper were supported by this Council at the University of British Columbia through Grant No. 1498. Canada: All-Union Scientific Institute of Irrigation and Hydraulics of the USSR. Translated from Gidrotekhnicheskoe Stoitel'stvo, No. 6, pp. 22–27, June, 1968.  相似文献   
42.
One of the three national games of Ireland, hurling is a contact team sport (15 a side) played with a metre long ash stick and a small hard leather ball. Over a 12 month period, 413 players were treated for hurling-related injuries at Cork Regional Hospital. While hand and facial trauma predominate, the proportion between the two sites has changed substantially from previous reports with a reduction in the level of facial injuries. The wearing of a helmet, and optionally a supplementary faceguard, is seen to have contributed to this trend. Despite this welcome reduction of facial injuries, a certain resistance to the use of protective headgear is evident, particularly among older players.  相似文献   
43.
对4点加载的W型梁进行试验,分析抗弯构件在加载作用下进行加固时的性能和承载力。试验结果显示:对于侧向扭转屈曲主导的破坏模式下的大跨构件,未加固梁的预加载力增加53%会导致加固梁的侧向屈曲荷载最多减少14.2%,但是预加载对构件极限荷载没有影响。对相同加固方式下跨度较短的构件进行试验发现:未加固梁的预加载增加50%会导致加固梁的极限承载力减少13%。然后,当构件在加载或者不加载情况下进行加固时,其挠曲变形变化并不大。对于由弯曲屈服主导的破坏模式下的构件,预加载对于加固构件的极限承载力并没有影响。  相似文献   
44.
数字电位器在可接受8位分辨率的应用中,可作为极佳的数控分压器,例如Analog Devices的AD5160。本篇设计实例介绍在需要更高分辨率的应用中如何使用CMOS DAC作为分压器。  相似文献   
45.
The economic relationship between China and Myanmar is regarded as a win–win cooperation. However, Chinese investments, especially in extractive and natural resource sectors, are associated with a number of unwanted environmental consequences. Moreover, the environmental impact assessment (EIA) quality of Chinese enterprises has often been criticized. EIA identifies adverse impacts to the environment through evidence-based decision making. On this basis, this paper provides an evaluation of Chinese EIA performance within the natural resources sector through a structured review of 15 environmental impact statements (EISs). This research also evaluates the EISs of the three largest and most controversial projects, the Myitsone Hydropower Dam, Lappadaung Copper Mine and Sino-Myanmar oil and gas pipelines. The findings reveal several omissions, inadequacies and deficiencies in all the projects with a significant number of EISs falling short of satisfactory quality. Through the analysis, the paper summarizes the factors affecting the EIA performance and proposes feasible recommendations to improve EIA practices in Chinese development projects in Myanmar.  相似文献   
46.
The self-assembly of short peptides into catalytic amyloid-like nanomaterials has proven to be a powerful tool in both understanding the evolution of early proteins and identifying new catalysts for practically useful chemical reactions. Here we demonstrate that both parallel and antiparallel arrangements of β-sheets can accommodate metal ions in catalytically productive coordination environments. Moreover, synergistic relationships, identified in catalytic amyloid mixtures, can be captured in macrocyclic and sheet-loop-sheet species, that offer faster rates of assembly and provide more complex asymmetric arrangements of functional groups, thus paving the way for future designs of amyloid-like catalytic proteins. Our findings show how initial catalytic activity in amyloid assemblies can be propagated and improved in more-complex molecules, providing another link in a complex evolutionary chain between short, potentially abiotically produced peptides and modern-day enzymes.  相似文献   
47.
Chlorine-based disinfectants protect pool water from pathogen contamination but produce potentially harmful halogenated disinfection by-products (DBPs). This study characterized the bioaccumulation and elimination of exhaled DBPs post-swimming and investigated changes in exhaled breath profiles associated with chlorinated pool exposure. Nineteen participants provided alveolar-enriched breath samples prior to and 5, 90, 300, 510, and 600 minutes post-swimming. Known DBPs associated with chlorinated water were quantitated by thermal desorption-gas chromatography-mass spectrometry. Two distinct exhaled DBP elimination profiles were observed. Most participants (84%) reported peak concentrations immediately post-swimming that reduced exponentially. A sub-group exhibited a previously unobserved and delayed washout profile with peak levels at 90 minutes post-exposure. Metabolomic investigations tentatively identified two candidate biomarkers associated with swimming pool exposure, demonstrating an upregulation in the hours after exposure. These data demonstrated a hitherto undescribed exhaled DBP elimination profile in a small number of participants which contrasts previous findings of uniform accumulation and exponential elimination. This sub-group which exhibited delayed peak-exhaled concentrations suggests the uptake, processing, and immediate elimination of DBPs are not ubiquitous across individuals as previously understood. Additionally, non-targeted metabolomics highlighted extended buildup of compounds tentatively associated with swimming in a chlorinated pool environment that may indicate airway responses to DBP exposure.  相似文献   
48.
Heritage sites are an important part of understanding our role in history. They have the potential to teach us important lessons, such as where we came from and subsequently, the people it has made us today. As members of a large, heritage-led, regeneration project, we are working with the Hafod–Morfa Copperworks, a heritage site in the Lower Swansea Valley where there is not much to see or hear. The few ruins at the site make it difficult to imagine what the site would have been like back in its heyday. Our goal at the site is to draw people together, not to view a finished piece of curated heritage, but rather, to start conversations about their memories and the significance of the site to them and to discover what they would like to see at the site in the future. The technology we are producing is about engaging with the local community and stakeholders as groups to provoke discussion. This contrasts with previous uses of mobile guides which only attempt to be tourist aids. In this article, we report on two prototype technologies we have developed to help accomplish this task. Throughout the article, we discuss how and why designing performative technologies could help encourage people to visit, socialise and communicate within the area. Our early results suggest that expressive performative technologies are good at gaining spectators’ attention and encouraging an active engagement between performer and spectator.  相似文献   
49.
Multiferroic materials have driven significant research interest due to their promising technological potential. Developing new room‐temperature multiferroics and understanding their fundamental properties are important to reveal unanticipated physical phenomena and potential applications. Here, a new room temperature multiferroic nanocomposite comprised of an ordered ferrimagnetic spinel α‐LiFe5O8 (LFO) and a ferroelectric perovskite BiFeO3 (BFO) is presented. It is observed that lithium (Li)‐doping in BFO favors the formation of LFO spinel as a secondary phase during the synthesis of LixBi1?xFeO3 ceramics. Multimodal functional and chemical imaging methods are used to map the relationship between doping‐induced phase separation and local ferroic properties in both the BFO‐LFO composite ceramics and self‐assembled nanocomposite thin films. The energetics of phase separation in Li doped BFO and the formation of BFO‐LFO composites are supported by first principles calculations. These findings shed light on Li's role in the formation of a functionally important room temperature multiferroic and open a new approach in the synthesis of light element doped nanocomposites for future energy, sensing, and memory applications.  相似文献   
50.
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