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91.
China is in the process of establishing a national emissions trading system (ETS). Evaluating the implementation effectiveness of the seven pilot ETSs in China is critical for designing this national system. This study administered a questionnaire survey to assess the behaviour of enterprises covered by the seven ETS pilots from the perspective of: the strictness of compliance measures; rules for monitoring, reporting and verification (MRV); the mitigation pressure felt by enterprises; and actual mitigation and trading activities. The results show that the pilot MRV and compliance rules have not yet been fully implemented. The main factors involved are the lack of compulsory force of the regulations and the lack of policy awareness within the affected enterprises. Most enterprises have a shortage of free allowances and thus believe that the ETSs have increased their production costs. Most enterprises have already established mitigation targets. Some of the covered enterprises are aware of their own internal emission reduction costs and most of these have used this as an important reference in trading. Many enterprises have accounted for carbon prices in their long-term investment. The proportion of enterprises that have participated in trading is fairly high; however, reluctance to sell is quite pervasive in the market, and enterprises are mostly motivated to trade simply in order to achieve compliance. Few enterprises are willing to manage their allowances in a market-oriented manner. Different free allowance allocation methods directly affect the pathways enterprises take to control emissions.
Key policy insights
In the national ETS, the compulsory force of ETS provisions should be strengthened.
A reasonable level of free allowance shortage should be ensured to promote emission reduction by enterprises.
Sufficient information should be provided to guide enterprises in their allowance management to activate the market.
To promote the implementation of mitigation technologies by enterprises, actual output-based allocation methods should be used.
The government should use market adjustment mechanisms, such as a price floor and ceiling, to ensure that carbon prices are reasonable and stable, so as to guide long-term low carbon investment.
92.
Abstract. The so-called 'covering behaviour' of echinoids is known to vary with habitat according to the types of covering items available, but the full extent of the role played by habitat characteristics in this behaviour is not known. Moreover, whether or not different species inhabiting similar environmental conditions and habitats also show similar patterns of this particular behaviour has yet to be investigated. In this study, two prominent west coast echinoid species, Paracentrotus lividus and Strongylocentrotus purpuratus , were examined with respect to covering behaviour and spatial organisation. Populations of both species are found in exposed intertidal zones, occupying boreholes within tidepools. Important similarities were found in the spatial organisation of both species' populations, with lowest densities in upper shore pools. However, the size distributions of the two populations differed significantly; P. lividus within upper shore pools were significantly larger than those in mid or lower shore pools, whereas S. purpuratus on the lower shore were significantly larger than those at other shore heights. We found significant between-species variability in covering item use, although the number of covering items available at both sites was not significantly different. For example, greater densities of covering items were used by P. lividus than by S. purpuratus . We also found that the percent of echinoid surface area covered varied significantly in space for both species. These data emphasise the complex and multifaceted nature of covering behaviour, but most importantly, they also strongly suggest that habitat characteristics can only partly explain the extent of this behavioural variability amongst echinoid species. 相似文献
93.
对哈萨克斯坦几次M≥6强震前动物行为异常的有关资料进行了研究,发现动物(20种)是通过其行为反应的变化对地震作出响应的。另外,在阿拉木图的山前地带(地震活动值大于9),对动物血液学和生物学指数上的动态变化进行了观察。 相似文献
94.
95.
粘土矿物研究在塔里木盆地石油勘探中的应用 总被引:1,自引:1,他引:1
以塔里木盆地粘土矿物的分布特征及其组合形式、演化与形成机理为依据,探讨了粘土矿物在地层划分对比中的应用及其与有机质热演化、成岩阶段的关系和对储层物性的影响。研究表明,在侏罗系和白垩系两个不同古环境中形成的粘土矿物及其组合特征,为地层对比提供了一定的证据。泥岩中伊利石/蒙皂石间层中蒙皂石含量的纵向变化与有机质热演化及成岩阶段的关系不大。对储层物性影响不大但有利于储集性能的是以高岭石为主的粘土矿物组合类型及粘土矿物的早期自生(伊利石/蒙皂石间层矿物)衬垫式以及非自生(伊利石)衬垫式产状。 相似文献
96.
M. Pistorino F. Nestola T. Boffa Ballaran M. C. Domeneghetti 《Physics and Chemistry of Minerals》2006,33(8-9):593-600
The unit-cell parameters of two columbite samples along the (Fe,Mn)Nb2O6 solid solution were measured by means of high-pressure single-crystal X-ray diffraction up to pressures of 7 GPa. The compressional behaviour of these minerals was studied as a function of composition and degree of order. The P–V data of all the samples were fitted with a third-order Birch–Murnaghan equation of state. For the two samples with different compositions but identical degree of order the substitution of Mn for Fe causes a decrease of the bulk modulus K
T0, from 153(1) to 146(1) GPa, without any effect on the pressure first derivative K′. For the two samples with the same composition, cation ordering causes an increase of the bulk modulus from 149(1) to 153(1) GPa and of the pressure first derivative from 4.1(2) to 4.8(3). The compressional behaviour is anisotropic with a linear axial compressibility scheme β
b
> β
c
≥ β
a
for all samples, regardless of composition and degree of order. Such anisotropy increases sligthly with increasing Mn content. 相似文献
97.
S.N. De Sousa 《Estuarine, Coastal and Shelf Science》1983,16(3):299-308
Behaviour of silicate, nitrate and phosphate in the Mandovi Estuary was studied during the premonsoon season. The study shows that silicate is removed from the water column while nitrate showed an internal source. This nitrate source has been identified as the wash water from an iron ore screening plant which discharges the muddy waste directly into the river. Applying mixing relations, the distribution of this nitrate both up- and downstream of the outfall has been studied. Phosphate showed very low concentrations in the low salinity region; however, its concentration increased slightly towards the higher salinity region. 相似文献
98.
Ultrasonically tagged flounders were tracked in the estuary of the River Bann, Northern Ireland, for periods of between 2 and 12 h (11 fish for a total of 92 h and 2·5 km), during their summer residence. Positions were determined by triangulation with two receivers.All fish remained within 400 m of the release point; on average flounders moved about 270 m during one tidal cycle, equivalent to 830 body lengths, or just over 1 body length per minute. Movements were most likely at dusk, but other parameters were not contingent upon time of day, although no data were gathered at dawn. Frequency, direction, distance, speed and duration of movement and turn rate were all significantly contingent upon state of the tide. The movement data are interpreted in terms of feeding behaviour, supported by results from other parts of the study. At high tide flounders made active but meandering searches for food on the inundated mudflats. Similar but faster searches heading downstream on falling tides reflected (a) completion of feeding while littoral invertebrates were still available and (b) avoidance of stranding. Flounders made infrequent but long and linear passages downstream at low tide, when they tended to bury themselves at the edge of the main channel where there was little food. Subsequently, the fish followed the rising tide upstream so that the cycle of movements kept most fish in the same area of the estuary in the short term. It is suggested that tolerance of changing salinities enables flounders, more than other flatfish species, to exploit dense populations of estuarine intertidal invertebrates as food. 相似文献
99.
The ability of discrete element models to describe quantitatively (and not only qualitatively) the constitutive behaviour of a dense sand is assessed in this paper. Two kinds of 3D discrete models are considered. Both consider spheres as elementary particles. Nevertheless, the first model implements a contact law with rolling resistance whereas the second takes into account clumps made of two spheres. The discrete models are calibrated and validated from mechanical tests performed on a dense Hostun sand with a true triaxial apparatus. The calibration is carried out from axisymmetric drained compression tests, while the validation is discussed from monotonic and cyclic stress proportional loading paths and from a circular stress path in the deviatoric stress plane. The quality of the predictions of the discrete models are evaluated by comparison with the predictions given with advanced phenomenological constitutive relations, mainly an incrementally non-linear relation. Predictions given by the discrete models are remarkable, particularly when it is put in perspective with respect to the very few number of mechanical tests required for their calibration. However, these results and conclusions were reached in enabling conditions, and some limitations of such discrete models should be kept in mind. 相似文献
100.
An increasing number of publications focus on social vulnerability, resilience, and adaptation (SVRA) towards natural hazards and climate change. Despite this proliferation of research, a systematic understanding of how these studies are theoretically grounded is lacking. Here, we systematically reviewed 4432 articles that address SVRA in various disciplinary fields (e.g. psychology, sociology, geography, mathematics) for various hazards, including floods, droughts, landslides, storm surges, wildfires, tsunamis, earthquakes, and volcano eruptions. We focus on the extent to which these studies explicate the frameworks, theoretical constructs or theories they rely on. Surprisingly, we found that about 90% of the reviewed studies do not explicitly refer to a theoretical underpinning. Overall, theories focusing on individuals’ SVRA were more frequently used than those focusing on systems, society, groups, and networks. Moreover, the uptake of theories varied according to the hazard investigated and field of knowledge, being more frequent in wildfire and flood studies and articles published in social science journals. Based on our analysis, we propose a reflexive handling of theories to foster more transparent, comparable, and robust empirical research on SVRA. 相似文献