4,462 research outputs found

    De la petite à la grande patrie, la question de l'identification chez les élèves Yi et Han dans la préfecture des Yi de Liangshan (Sichuan): Asymétrie identitaire et effets de contexte

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    International audienceThe government of the PRC has led the project of identification and institutionalization of its people in different "ethnic groups" (minzu) during the 1950s. Under this political context, this article concerns the double identification of the ethnic minority (shaoshuminzu) Yi of Liangshan : as member of the Chinese nation and as member of an ethnic minority. Taking support on a survey in the form of questionnaire addressing to students Han/ Yi in several schools in Liangshan, we aim to measure the context effect, linking to the degree of ethnic coeducation, on the auto-identification of these students. Overall, Yi's integration in the chinese society is obvious. However, the degree of ethnic coeducation in the different schools plays a part in the mutual representations (Han and Yi) and comes with a variable symmetry of those representations in the process of mutual gratitude.En Chine, les autorités ont mené le projet d'identification et d'institutionnalisation de la population en différents " groupes ethniques " (minzu) dans les années 1950. Dans le contexte politique des débuts de la République populaire de Chine, cet article porte sur l'enjeu de la double identification d'une ethnie minoritaire (shaoshuminzu), celle des Yi de Liangshan : à la fois membres de la nation chinoise et membres d'une ethnie minoritaire. Prenant appui sur une enquête sous forme de questionnaire menée auprès des élèves Han/Yi de plusieurs établissements à Liangshan, nous cherchons à mesurer l'effet de contexte, lié au degré de mixité ethnique, sur l'auto-identification de la part de ces élèves. Globalement, l'intégration des Yi dans la société chinoise est manifeste. Toutefois, le degré de mixité ethnique des différents établissements joue un rôle dans les représentations des uns et des autres (Han et Yi) et s'accompagne d'une symétrie variable de ces représentations dans le processus de reconnaissance mutuelle

    Analysis on Science Popularization Mode in Ethnic Villages: A Case Study on Youshuihe Town in Youyang Tujia and Hmong Autonomous County

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    During popularization of science in ethnic villages, new science popularization modes unique to minorities should be explored considering the prominent problem that the existing science popularization mode, restricted by such factors as ethnic groups, diverse cultures and territorial environments, has become incapable of adapting to and satisfying local demands for science popularization. Based on a case study on science popularization in Youshuihe Town, Chongqing, a new mode, which gears to the multicultural society, centers upon ethnic villages and villagers’ pursuit for science popularization, integrates various useful resources from the perspectives of personnel, content selection, management mechanism, ethnic culture and natural environment, and aims at improving the scientific quality of ethnic villages and villagers, will be investigated into in this paper

    Photostimulated tert-butylation of quinolines, quinolinium salts, quinoline N-oxides, N-benzylideneanilines, and azobenzenes

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    Photolysis of tert-butylmercury halides with quinolines, N-methyl or N-methoxyquinolinium salts, or quinoline N-oxides leads to alkylation via the intermediacy of adduct radicals or radical cations. The system t-BuHgCl/KI is a unique one because of the presence of both a mild oxidizing agent (t-BuHgI) and reducing agent (I[superscript]- or t-BuHgI[subscript]2[superscript]-). 4-Substituted quinolines, such as 4-chloro- or 4-methylquinoline, undergo only substitutive alkylation (at C-2). With 2-substituted quinolines, reductive alkylation (at C-4) occurs in the presence of KI. With quinoline itself, attack of t-Bu· at C-2 leads to the substituted product, but attack at C-4 leads mainly to a reduced quinoline derivative, 4-tert-butyl-1,4-dihydroquinoline which reacts rapidly in the presence of PTSA and t-BuHgI to form 2,4-di-tert-butyl-1,2,3,4-tetrahydroquinoline. Photolysis of t-BuHgCl/KI with N-methylquinolinium salts gives mainly reductive alkylation products. With N-methoxyquinolinium perchlorates, reductive tert-butylation occurs in the presence of KI, followed by, in most cases, demethoxylation with aromatization of the quinoline ring. Deoxygenation of quinoline N-oxides may occur before tert-butylation with t-BuHgCl/KI in Me[subscript]2SO, while photolysis of tert-butylmercury halides with 2-chloroquinoline N-oxide forms the dimer of the adduct radical. With quinoline N-oxide and its 4-substituted derivatives, the addition of DABCO yields the oxidative alkylation products, 2-tert-butylquinoline N-oxides.;Reaction of t-BuHgI with N-benzylideneanilines gives exclusively the reductive alkylation products. Quantitative yields of the products are obtained in the presence of t-BuHgI/KI/PTSA. Photostimulated tert-butylation of azobenzenes by t-BuHgI forms reductive alkylation products. Addition of K[subscript]2S[subscript]2O[subscript]8 speeds up the alkylation. The effects of I[superscript]- on the reaction are discussed

    Heavy-Duty Vehicles Modeling and Factors Impacting Fuel Consumption.

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    A conventional heavy-duty truck PSAT model was validated and incorporated into the Powertrain System Analysis Toolkit (PSAT). The truck that was modeled was a conventional over-the-road 1996 Peterbilt tractor, equipped with a 550 hp Caterpillar 3406E non exhaust gas circulation (EGR) engine and an 18-speed Roadranger manual transmission. A vehicle model was developed, along with the model validation processes. In the engine model, an oxides of nitrogen (NOx) emissions model and a fuel rate map for the Caterpillar 3406E engine were created based on test data. In the gearbox model, a shifting strategy was specified and transmission efficiency lookup tables were developed based on the losses information gathered from the manufacturer. As the largest mechanical accessory model, an engine cooling fan model, which estimates fan power demand, was integrated into the heavy-duty truck model. Experimental test data and PSAT simulation results pertaining to engine fuel rate, engine torque, engine speed, engine power and NOx were within 5% relative error. A quantitative study was conducted by analyzing the impacts of various parameters (vehicle weights, coefficients of rolling resistance and the aerodynamic drag) on fuel consumption (FC) for the Peterbilt truck. The vehicle was simulated over five cycles which represent typical vehicle in-use behavior. Three contributions were generated. First, contour figures provided a convenient way to estimate fuel economy (FE) of the Peterbilt truck over various cycles by interpolating within the parameter values. Second, simulation results revealed that, depending on the circumstances and the cycle, it may be more cost effective to reduce one parameter value (such as coefficient of aerodynamic drag) to increase FE, or it may be more beneficial to reduce another (such as the coefficient of rolling resistance). Third, the amount of the energy consumed by auxiliary loads was found to be highly dependent upon the driving cycles. The ratios between average auxiliary power and average engine power were found to be 71.0%, 17.1%, 15.3%, 12.4% and 11.43% for creep, transient, UDDS, cruise and HHDDT_s cycles, respectively. A hybrid electric bus (HEB) also was modeled. The HEB that was modeled was a New Flyer bus with ISE hybrid system, a Cummins ISB 260H engine and a single-reduction transmission. Information and data were acquired to describe all major components of the HEB. The engine model was validated prior to modeling of the whole vehicle model. The load-following control strategy was utilized in the energy management system. Experimental data and PSAT simulated results were compared over four driving schedules, and the relative percent of errors of the FC, FE, CO2 and NOx were all within 5% except for the FE and NOx of the Manhattan cycle, which were 6.93% and 7.13%, respectively. The high fidelity of this model makes it possible to evaluate the FE and NOx emissions of series hybrid buses for subsequent PSAT users

    Learning Attitudes Towards and Learning Experiences in Online Teaching During the Pandemic

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    Many problems with online teaching during the COVID-19 pandemic need to be solved: the unidirectional transmission of information, the immaturity of teaching platforms, the alienation in time and space between teachers and students, and the students’ inconsistent learning conditions. By taking a quantitative and qualitative approach, this study explored the factors that impact students’ learning attitudes and learning experiences in real-time online teaching, with the purpose of improving students’ learning and future online teaching. The results show that the average scores of university students’ learning attitudes and learning experiences in real-time online learning are higher than the standard scores. Moreover, significant differences have been found in gender, the availability of independent learning space, the parents’ requirements, discipline, and grade. Online teaching has increased students’ academic workload and brought great challenges to students’ attention, self-regulated learning abilities, as well as physical and mental health
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