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Azodicarbonamide (ADC) is a type of azo compound with outstanding application performance, it is always used as a blowing agent in the production of foamed plastics. Based on previous studies, it has been considered harmless in its practical application process. Nevertheless, our research has overturned this standpoint and denoted the special exothermic behavior of ADC under specific use processes, especially when it was placed in a high-pressure system. In this study, a simultaneous thermogravimetric analyzer (STA) was employed to preliminarily evaluate the thermal stability of ADC under atmospheric pressure. Followed with calorimetric experiments by high-pressure differential scanning calorimetry (HP DSC), the exothermic behaviors of ADC under different initial furnace pressures were investigated. The obtained results revealed that the thermal decomposition rate of ADC linearly increases along with increasing testing pressure, which shows a highly autocatalytic characteristic. The peak power of DSC curve breathtakingly reached 73 W/g when the initial testing pressure was set at 4 MPa, and the overall decomposition heat reached 1261 J/g with the scanning rate at 4 °C/min. Furthermore, the decomposition mechanism, thermal hazards, and explosion potential were comprehensively evaluated in this study for the first time. 相似文献
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不同基因型杨树的光合特征与臭氧剂量的响应关系 总被引:1,自引:1,他引:0
采用开顶式气室装置研究不同臭氧浓度对3种基因型杨树(‘546’、‘90’和‘84K’)光合作用特征的影响.结果表明,随着O_3浓度的升高,净光合速率(P_n)、蒸腾速率(T_r)、水分利用效率(WUE)、电子传递速率(ETR)、PSⅡ反应中心激发能捕获效率(F'_v/F'_m)、光化学猝灭系数(q P)、PSⅡ实际光化学量子效率(Phi PS2)、叶绿素a(Chla)、叶绿素b(Chlb)、叶绿素总量(Chla+b)和类胡萝卜素(Car)均显著降低,胞间CO_2浓度(c_i)显著升高,气孔导度(G_s)变化不显著.不同基因型杨树各项光合生理指标之间均存在显著性差异,基因型‘546’各项光合指标(除G_s外)与O_3剂量(AOT40,小时O_3浓度大于40nmol·mol~(-1)的累计值)间具有显著的线性相关关系(P0.01),并且光合色素含量随着O_3浓度的升高而显著降低.但高浓度O_3对基因型‘90’和‘84K’光合色素影响不显著.从多数光合特征指标特别是叶绿素总量的O_3剂量线性响应关系来看,基因型‘546’表现出最大的斜率,基因型‘90’次之,基因型‘84K’斜率最小,因而可得知随着O_3浓度升高,三者的臭氧敏感性为‘546’‘90’‘84K’.该研究结果为O_3污染环境下杨树基因型筛选与培育,以及保护杨树免受O_3伤害提供科学依据. 相似文献
908.
Abstract Since the reform and opening up, China’s export trade has maintained a rapid growth; meanwhile, China’s energy consumption has been increasing sharply. “High export and high energy consumption” has become the feature of China’s trade and economic development. In this paper, based on the input–output analysis approach, the authors have conducted an empirical study on the export trade and energy consumption of 21 trade industrial sectors. The results show that, China is a big net exporter of embodied energy. Assuming that the export growth rate of embodied energy maintains to be about 23.6%, the average annual growth rate of the past 32 years, and based on the input–output data of 2005, by 2030 China’s net export of embodied energy would be over eight times more than the aggregate energy production, which is obviously infeasible. As a country of very low per capita energy, China must change its export pattern, encourage or restrain the export of different industrial sectors according to their energy consumption intensity, and promote structural change of energy– efficient exported products, so as to achieve the sustainable development. Accordingly, the authors put forward some suggestions. 相似文献
909.
This paper explores, explains and discusses issues around the dilemma between local conservation of natural resources (often, endangered species and habitats) and tourism needs in Africa. Often and in constitutional terms, local people have a right to exploit and use resources endowed in their local area. However, tourists often are interested in viewing the vegetation and animal resources undisturbed. Inevitably, there is an undeclared animosity of values and interests between local communities and tourists and state agencies. As a result, the dilemma is thus of governance. The purpose of this paper is to demonstrate the governance dilemma of resource utilization and tourism in Africa in a bid to create an informed stewardship framework for sustainability. This is achieved by way of case studies and narratives from Africa. As such, this paper will be a review literature on how different communities perceive tourism and derive livelihoods from their immediate environment. It also explains how the external factors influence local needs and interests. A more sustainable and operational framework that reduces friction among stakeholders is suggested. 相似文献
910.
《International Journal of Sustainable Engineering》2013,6(2):121-132
Today, energy occupies a pivotal position around which all socio-economic activities revolve. No energy means no life, and supply of energy in a cheap, plentiful, long-sustainable and environmentally safe form is a boon for everyone. In the light of rising cost of oil and fears of its exhaustion coupled with increased pollution, the governments worldwide are deliberating and making huge strides to promote renewable energy sources such as wind. Integration of wind machines with the diesel plants is pursued widely to reduce dependence on fossil-fuel-produced energy and to reduce the release of carbon gases that cause global climate change. The literature indicates that commercial/residential buildings in the Kingdom of Saudi Arabia (KSA) consume an estimated 10–40% of the total electric energy generated. The aim of this study is to analyse wind-speed data of Dhahran (East-Coast, KSA) to assess the economic feasibility of utilising autonomous hybrid wind–diesel power systems to meet the electrical load of 100 typical residential buildings (with annual electrical energy demand of 3512 MWh). The monthly average wind speeds range from 3.3 to 5.6 m/s. The hybrid systems simulated consist of different combinations of 600 kW commercial wind machines supplemented with diesel generators. The National Renewable Energy Laboratory's hybrid optimisation model for electric renewables software was employed to perform the techno-economic analysis. The simulation results indicate that for a hybrid system comprising 600 kW wind capacity together with a 1.0 MW diesel system (two 500 kW units), the wind penetration (at 50 m hub-height, with 0% annual capacity shortage) is 26%. The cost of generating energy (COE, $/kWh) from this hybrid wind–diesel system was found to be 0.070 $/kWh (assuming diesel fuel price of 0.1 $/l). The study exhibits that for a given hybrid configuration, the number of operational hours of diesel generator sets (gensets) decreases with an increase in the wind-farm capacity. Concurrently, emphasis has also been placed on wind penetration, un-met load, effect of hub-height on energy production and COE, excess electricity generation, percentage fuel savings and reduction in carbon emissions (relative to diesel-only situation) of different hybrid systems, cost breakdown of wind–diesel systems, COE of different hybrid systems, etc. 相似文献