INTERNATIONAL JOURNAL OF BILINGUAL EDUCATION AND BILINGUALISM,2019年22(3):290-302 ISSN：1367-0050
Tsung, Linda T. H.
[Zhang, Lubei] Southwest Jiaotong Univ, Sch Foreign Languages, Chengdu, Sichuan, Peoples R China.;[Tsung, Linda T. H.] Univ Sydney, Dept Chinese Studies, Sydney, NSW, Australia.
[Tsung, Linda T. H.] Univ Sydney, Dept Chinese Studies, Sydney, NSW, Australia.
Bilingual education;family language practice;Tibetan students;government language policy
This paper explores the intersection between government bilingual education policy in schools for Tibetan students and family language practices at home and looks at the implications of such practices. Summaries of empirical data and critical analysis are reported from Qinghai in China. A field study was conducted in Tibetan areas in Qinghai between 2013 and 2016. This fieldwork included school visits, observation and interviews undertaken with teachers, principals and parents. This paper draws from findings based on interviews with Tibetan parents. The results of this research provide insights into the links between bilingual education programs and family members' decision-making processes. A major conclusion is that there are conflicts between top-down government language policies and bottom-up family language practice. These conflicts arise as Government policies discount the crucial support system parents provide for children's language learning at home and bilingual education programs in schools. Additionally, socio-economic and educational factors outside the scope of Government Language Education policies may have a significant influence on bilingual education practices, multilingual achievement and the career success of the younger generation of Tibetans.
Green and renewable, wind is one of the major ways to produce power. However, natural wind used for tunnel ventilation is often neglected. Natural wind is usually regarded as resistance. Every year, unchanging ventilation mode and unreasonable control strategy lead to huge energy consumption and economic loss In China. This paper mainly discusses and analyzes the current situation of energy consumption in extra-long tunnel operation ventilation in China. It proposes the natural wind utilization in extra-long segmented tunnels. Therefore, a scientific and theoretical calculation method for extra-long tunnels located in climate separation zone is presented in this paper. Principles of natural wind in each tunnel section are obtained based on long-term monitored meteorological factors. A feasible optimized energy-saving ventilation strategy is put forward, which utilizes natural wind and will minimize the operation energy consumption. It is concluded that, the results about operation energy consumption from this paper can provide useful technical supports in design, operation and management for tunnels all over the world. (C) 2015 Elsevier Ltd. All rights reserved.
air density;construction labor intensity;equivalent PIO2;high-altitude;oxygen consumption;oxygen supply
The low atmospheric pressure and low oxygen content in high-altitude environment have great impacts on the functions of human body. Especially for the personnel engaged in complicated physical labor such as tunnel construction, high altitude can cause a series of adverse physiological reactions, which may result in multiple high-altitude diseases and even death in severe cases. Artificial oxygen supply is required to ensure health and safety of construction personnel in hypoxic environments. However, there are no provisions for oxygen supply standard for tunnel construction personnel in high-altitude areas in current tunnel construction specifications. As a result, this paper has theoretically studied the impacts of high-altitude environment on human bodies, analyzed the relationship between labor intensity and oxygen consumption in high-altitude areas and determined the critical oxygen-supply altitude values for tunnel construction based on two different standard evaluation systems, i.e., variation of air density and equivalent PIO2. In addition, it has finally determined the oxygen supply standard for construction personnel in high-altitude areas based on the relationship between construction labor intensity and oxygen consumption.
Saving energy is a major challenge for the development and safety of the world. Researchers at home and abroad have been continuously working on energy saving technology in the tunnel ventilation for decades. Based on segmented longitudinal ventilation for extra-long road tunnels, the main ventilation mode and utilization method of natural wind energy in extra-long road tunnel were analyzed in this paper. In addition, the possible velocity distribution of natural wind in each section under wind pressure was investigated. Principles of natural wind in each tunnel section were studied based on long-term monitored meteorological factors. Accordingly, a fan equipment configuration method with high guaranteed rate during tunnel operation was proposed. A calculation method for energy-saving network ventilation in the tunnels was established. A feasible and efficient optimized energy-saving ventilation strategy was proposed, which utilizes natural wind and reduces the operation energy consumption. Thus, the annual energy saving in ventilation can reach up to 43.2% compared to previous energy costs when the intelligent ventilation system works. The research results can properly combine natural wind energy with mechanical ventilation to realize the smart self-energy saving in extra-long tunnels.
The global avalanche characteristics (the sum-of-squares indicator and the absolute indicator) measure the overall avalanche characteristics of a cryptographic Boolean function. Sung et al. (1999) gave the lower bound on the sum-of-squares indicator for a balanced Boolean function satisfying the propagation criterion with respect to some vectors. In this paper, if balanced Boolean functions satisfy the propagation criterion with respect to some vectors, we give three necessary and sufficient conditions on the auto-correlation distribution of these functions reaching the minimum the bound on the sum-of-squares indicator. And we also find all Boolean functions with 3-variable, 4-variable, and 5-variable reaching the minimum the bound on the sum-of-squares indicator.
High energy consumption, high resource consumption and high greenhouse gas (GHG) emission are characteristics of tunnel construction. Different from ground engineering, tunnel is highly influenced by surrounding rock. However, surrounding rock has never been mentioned in previous published studies on GHG emissions in tunnels. In order to evaluate the effect of surrounding rock conditions on GHG emissions, this study expounded the relationship between tunnel designs and rock mass classifications. Besides, five different surrounding rock conditions and tunnel lining designs of a real tunnel in China were introduced in detail. Life cycle assessment (LCA) was used to analyze the GHG emissions in five tunnels with different surrounding rock. The tunnels with worse rock conditions generate more GHG emissions in construction, while the emissions are between 6220 t- 17,010 t CO2 eq. More than 60% of the GHG emissions are from materials. For the first time, the importance of surrounding rock conditions to GHG emissions in tunnels was clarified in this study. It has been found that emissions increased sharply in many cases after comparing the same construction for different surrounding rock conditions. Based on the defined relative contribution indexes, transition paths of GHG emission were ascertained. Rock mass and casting & lining are the major two emission transition processes when the rock mass conditions get weak. Over 69% of emission increment were from cement and steel. Three emission characteristics of tunnel construction affected by surrounding rock were summarized as: correlation of surrounding rock conditions, non-continuity of emission and non-consistency of emission transition path. (C) 2018 Elsevier Ltd. All rights reserved.