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1

Strict pseud-contraction strong convergence theorems for strict pseud-contractions

100%

Qin X. , Su Y.

Journal of Mathematics and Applications

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2008

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tom Vol. 30

137-149

EN

In this paper, we prove two strong convergence theorems for strict pseudocontractions in Hilbert spaces by hybrid methods. Our results extend and improve the recent ones announced by Nakajo and Takahashi [K. Nakajo, W. Takahashi,. Strong convergence theorems for nonexpansive mappings and nonexpansive semigroups, J. Math. Anal. Appl. 279 (2003), 372-379], Marino and Xu [G. Marino, H.K. Xu, Weak and strong convergence theorems for strict pseudo-contractions in Hilbert spaces, J. Math. Anal. Appl. 329 (2007), 336-346], Martinez-Yanes and Xu [C. Martinez-Yanes, H.K. Xu, Strong convergence of the CQ method for fixed point iteration processes, Nonlinear Anai. 64 (2006), 2400-2411] and some others.

2

Nuclear, renewables and low carbon growth: a comparative study on China, U.S., France and Japan

80%

Wang X. , Yu J. , Zhang M. , Qin X.

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tom 28

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nr 4

EN

Using the ARDL test and Granger approaches, this paper investigates long-term co-integration and causal relationships among nuclear, renewables, GDP and CO2 emissions in China, US, France and Japan. The findings reveal that the long-term coefficient of nuclear energy is smaller than renewable energy, indicating a relative advantage of nuclear power. However, the emission reduction effect of nuclear and renewables in China was not as much as compared to other nations. Moreover, causality from economic growth to nuclear or renewable energy existed in all countries, whereas no causality from nuclear energy to economic growth existed except in Japan. Therefore, giving priority to energy conservation and energy mix optimization is not likely to hurdle economic growth in China. However, greenness of the overall energy production process, augmentation of energy efficiency, technological progress in energy storage and internet, sustainable development of resource-society, and nuclear safety issues should be given priority in order to contribute to low-carbon growth in China.

3

Growth responses and non-structural carbohydrates in three wetland macrophyte species following submergence and de-submergence

80%

Qin X. , Li F. , Chen X. , Xie Y.

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2013

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tom 35

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nr 07

EN

We investigated the responses of growth and non-structural carbohydrates to submergence and de-submergence in three wetland macrophyte species. Survival rate, recovery ability, and soluble sugar and starch contents of flood-tolerant Polygonum hydropiper and of flood-sensitive Phalaris arundinacea and Carex argyi from Dongting Lake wetlands were investigated after 20, 40, and 60 days of complete submergence without light and 10 days after de-submergence. Plant dry weight and soluble sugar and starch contents decreased in all species during the submergence period. The decreases were slowest in P. hydropiper, intermediate in C. argyi, and most rapid in P. arundinacea. After 60 days of submergence, survival rates were 100, 50, and 0 % in P. hydropiper, C. argyi, and P. arundinacea, respectively. After recovery, plant dry weight increased in P. hydropiper and in C. argyi, but decreased in P. arundinacea. Compared to pre-submergence, soluble sugar contents generally increased and then remained relatively constant after recovery in all species, while starch content increased in P. hydropiper and decreased in P. arundinacea with increasing submergence time. For C. argyi, starch content decreased after recovery from the 20-day submergence, but increased after recovery from the 40- and 60-day submergences. These data illustrate mechanisms behind the flood tolerance of P. hydropiper and the sensitivity to flooding in P. arundinacea and C. argyi. These mechanisms include lower consumption and quicker accumulation of non-structural carbohydrates in flood-tolerant plants.

4

The impact of climate change and human activity on net primary production in Tibet

80%

Qin X. , Sun J. , Liu M. , Lu X.

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2016

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tom 25

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nr 5

EN

The Tibetan Plateau has faced environmental degradation in recent years due to intensified human activity and climate change. In this study, the dynamics of net primary production (NPP), annual mean temperature (AMT), annual mean precipitation (AMP), number of animals (NA), number of rural laborers (NRL), and animal husbandry (AH) were analyzed and the response of NPP to climate and human activity explored. The results show that NPP was increasing gradually from northwest to southeast and is similar to the distribution of AMP. In addition, NA, NRL, and AH cluster around Lhasa. Moreover, AMP had a negative correlation with NPP in Tibet while AMT has a positive effect on NPP. Moreover, because of the large number of livestock there is a negative relationship between NA and NPP in most Tibetan regions. Furthermore, it was found that human activity made a higher contribution to NPP in Tibet (24.73%) than climate factors (17.28%). It is, therefore, necessary to further explore the relationship between human activity and the vegetation dynamic in the region.