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Calculation of Scale of Fluctuation and Variance Reduction Function 被引量:2
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作者 闫澍旺 郭林坪 《Transactions of Tianjin University》 EI CAS 2015年第1期41-49,共9页
The scale of fluctuation is one of the vital parameters for the application of random field theory to the reliability analysis of geotechnical engineering. In the present study, the fluctuation function method and wei... The scale of fluctuation is one of the vital parameters for the application of random field theory to the reliability analysis of geotechnical engineering. In the present study, the fluctuation function method and weighted curve fitting method were presented to make the calculation more simple and accurate. The vertical scales of fluctuation of typical layers of Tianjin Port were calculated based on a number of engineering geotechnical investigation data, which can be guidance to other projects in this area. Meanwhile, the influences of sample interval and type of soil index on the scale of fluctuation were analyzed, according to which, the principle of determining the scale of fluctuation when the sample interval changes was defined. It can be obtained that the scale of fluctuation is the basic attribute reflecting spatial variability of soil, therefore, the scales of fluctuation calculated according to different soil indexes should be basically the same. The non-correlation distance method was improved, and the principle of determining the variance reduction function was also discussed. 展开更多
关键词 random field scale of fluctuation correlation function sample distance sample interval variance reduction function
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Effect of lung volume reduction surgery on early function of lung and pulmonary hemodynamics in COPD
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作者 侯生才 《外科研究与新技术》 2003年第2期107-107,共1页
Objective To evaluate the effects of lung volume reduction surgery (LVRS) on early lung function and pulmonary hemodynamics in severe chronic obstructive pulmonary disease (COPD). Methods 31 patients with severe COPD ... Objective To evaluate the effects of lung volume reduction surgery (LVRS) on early lung function and pulmonary hemodynamics in severe chronic obstructive pulmonary disease (COPD). Methods 31 patients with severe COPD underwent LVRS, bilateral LVRS in 11 patients and unilateral in 20 patients. The results of lung function (FEV1, RV, TLC), arterial blood gas analysis (PAO2, PACO2 ) and color Doppler echocardiography (CD,CI,FS,EF,PAP) were analyzed before and 3 month after LVRS in 26 cases. Results FEV1, RV and TLC were improved significantly after surgery ( P 【 0. 01). PaO2 increased (P 【 0. 05 ) and PaCO2, decreased postoperatively (P 【 0. 01). According to the Doppler echocardiography, there were no statistic differences in cardiac functions (CO, CI, FS, EF, and PAP) between pre- and post-operation. The 6-minute-walk-distance in 26 patients was (227 ± 88) m, significantly increased after surgery. Conclusion LVRS is effective in the treatment of patients with severe COPD. 3 months after operation, the 展开更多
关键词 LUNG Effect of lung volume reduction surgery on early function of lung and pulmonary hemodynamics in COPD of
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Ozone-Mediated Functionalization of Multi-Walled Carbon Nanotubes and Their Activities for Oxygen Reduction Reaction
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作者 Hengheng Xia Yexin Zhang +3 位作者 Chunlin Chen Wenlin Wu Ken Yao Jian Zhang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2016年第6期533-538,共6页
The functionalization of multi-walled carbon nanotubes (MWCNTs) by ozone treatment has been sys- tematically investigated by using Raman spectroscopy, transmission electron microscopy (TEM), Fourier transform inha... The functionalization of multi-walled carbon nanotubes (MWCNTs) by ozone treatment has been sys- tematically investigated by using Raman spectroscopy, transmission electron microscopy (TEM), Fourier transform inhared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), organic elemental anal- ysis (OEA) and Boehm titration. The results showed that the functionalization process occurred at defective sites (opened mouths, tube caps, debris, etc.) before opening caps and truncating walls, and finally the graphitic structure was deteriorated. The surface oxygen content first increased with the treatment time but kept at around 8.0 wt% after 5 h. The analysis of the distribution of oxygen-containing groups re- vealed that phenolic hydroxyl was gradually converted to carboxyl and lactone, The carboxyl was found to play a pivotal role to reduce the over-potentials when we used the functionalized MWCNTs as the cat- alyst for oxygen reduction reaction (ORR). 展开更多
关键词 Multi-walled carbon nanotubes Ozone oxidation functionalization Oxygen reduction reaction
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Recent progress in cathodic reduction-enabled organic electrosynthesis: Trends, challenges, and opportunities 被引量:4
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作者 Binbin Huang Zemin Sun Genban Sun 《eScience》 2022年第3期243-277,共35页
Compared with general redox chemistry,electrochemistry using the electron as a potent,controllable,yet traceless alternative to chemical oxidants/reductants usually offers more sustainable options for achieving select... Compared with general redox chemistry,electrochemistry using the electron as a potent,controllable,yet traceless alternative to chemical oxidants/reductants usually offers more sustainable options for achieving selective organic synthesis.With its environmentally benign features gradually being uncovered and studied,organic electrosynthesis is currently undergoing a revival and becoming a rapidly growing area within the synthetic community.Among the electrochemical transformations,the anodically enabled ones have been far more extensively exploited than those driven by cathodic reduction,although both approaches are conceptually attractive.To stimulate the development of cathodically enabled organic reactions,this review summarizes the recently developed reductive electrosynthetic protocols,discussing and highlighting reaction features,substrate scopes,applications,and plausible mechanisms to reveal the recent trends in this area.Herein,cathodic reduction-enabled preparative organic transformations are categorized into four types:reduction of(1)unsaturated hydrocarbons,(2)heteroatom-containing carbon-based unsaturated systems,(3)saturated C-hetero or C–C polar/strained bonds,and(4)hetero-hetero linkages.Apart from net electroreductive reactions,a few examples of reductive photo-electrosynthesis as well as paired electrolysis are also introduced,which offer opportunities to overcome certain limitations and improve synthetic versatility.The electrochemically driven,transition metal-catalyzed reductive cross-couplings that have been comprehensively discussed in several other recent reviews are not included here. 展开更多
关键词 reductive organic electrosynthesis Cathodic reduction reductive hydrogenation reductive functionalization reductive bond cleavage
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Functional Knowledge Representation Based on Problem Reduction
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作者 高济 《Journal of Computer Science & Technology》 SCIE EI CSCD 1992年第2期105-113,共9页
This paper proposes an approach for functional knowledge representation based on problem reduction,which represents the organization of problem-solving activities in two levels:reduction and reasoning.The former makes... This paper proposes an approach for functional knowledge representation based on problem reduction,which represents the organization of problem-solving activities in two levels:reduction and reasoning.The former makes the functional plans for problem-solving while the latter constructs functional units, called handlers,for executing subproblems designated by these plans.This approach emphasizes that the representation of domain knowledge should be closely combined with(rather than separated from)its use therefore provides a set of reasoning-level primitives to construct handlers and formulate the control strate- gies for executing them.As reduction-level primitives,handlers are used to construct handler-associative networks,which become the executable representation of problem-reduction graphs,in order to realize the problem-solving methods suited to domain features.Besides,handlers and their control slots can be used to focus the attention of knowledge acquisition and reasoning control. 展开更多
关键词 In high Functional Knowledge Representation Based on Problem Reduction MODE
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