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The forest ecological compensation is an important factor to balance the interests of different areas for sustainable development and environment protection. Mudanjiang City in Heilongjiang Province of China is rich of forest resources. The forestry coverage rate reached 62.3% in 2014, after forestry conservation program from 2002. The authors explored the factors impacted on forest ecological compensation in Mudanjiang City, which was a demonstration as a case study, through experts’ evaluation scores and AHP methodology to analyze the forest ecological compensation factors and lay the foundation for the establishment of ecological compensation mechanism. At the same time, we provided an example to explore the effective way and speed up the establishment of ecological compensation mechanism. The study found that the main factors that determined forest ecological compensation in Mudanjiang City were ecology and natural resources. Based on the analyses, some suggestions were put forward to promote the mechanism in a sustainable way.

In the early 1990s, Japanese scholars unexpectedly observed that single crystal changes into polycrystal in deuterium-implanted aluminum under electron irradiation, but never found the same phenomenon in the hydrogen-implanted aluminum. However, previous study of our group has proved that the polycrystalline phenomenon can also be observed in hydrogen-implanted aluminum during electron irradiation. In this paper, the behavior of inert gas bubbles in aluminum under electron irradiation is investigated, aiming to further explore the effects of ion species, electron voltage and the pressure of bubbles on the anomalous heat-releasing reaction of bubbles induced by electron irradiation. In the experiment, the transmission electron microscope (TEM) samples of pure aluminum were implanted with He+, Ne+, Ar+ respectively by ion accelerator at room temperature. The TEM is used to in-situ observe and investigate the evolution of microstructure and the change of selected electron diffraction patterns of gas bubbles during electron irradiation. The results show that gas bubbles form in aluminum sample after ion implantation. During 200 keV electron irradiation TEM results show that the three kinds of inert gas bubbles all coalesce, grow up and bust separately. Finally, lots of nanoscale black dots appear inside them. At the same time, the electron diffraction patterns change from single crystal diffraction spots to polycrystalline diffraction rings. The dark field images indicate that the diffraction rings are induced by these black dots. Moreover, from the characterization of the diffraction rings, it is known that these black dots are pure aluminum rather than aluminum oxide. Therefore, the possibility that the diffraction rings result from aluminum oxide is eliminated. It is assumed that a certain kind of heat-releasing reaction should happen when the gas bubbles are irradiated by electrons, which leads to the poly-crystallization of aluminum after electron irradiation. However, while helium bubbles are irradiated by electrons with an energy of 80 keV, no diffraction ring is observed after electron irradiation. The same phenomenon as that in the case of helium bubbles irradiated by 80 keV electrons is observed. When helium and argon mixed bubbles with polygonal shape are irradiated by 200 keV electrons, no diffraction ring is observed after electron irradiation either. The reason might be related to the energy of the electron beam and the pressure of gas bubbles separately. There should be a threshold value of electron voltage for the heat-releasing reaction. In addition, the pressure of the gas bubbles is also a key factor for the heat-releasing reaction. The heat-releasing phenomenon of gas bubbles reminds us of the sonoluminescence phenomenon. By model calculation, it is predicted that there is a plasma core in the bubble during sonoluminescence. According to the hint from researches of sonoluminescence, an assumption is made to explain the mechanism of heat-releasing reaction of gas bubbles during electron irradiation. It is that the implanted gas in high pressure bubbles in aluminum is excited into plasma during electron irradiation. When the energy of plasma in the bubbles is accumulated to a certain degree, the plasma is extinguished suddenly. In this process, a lot of heat is released to melt the aluminum, thus leading the aluminum to recrystallize.

Vanadium alloys are considered as the candidate materials for structure application in fusion reactors because of their low radiation-induced activation, high resistance to radiation damage, high thermal conduction, and low thermal expansion coefficient. Before these materials, which will be exposed to high-flux hydrogen and helium isotopes, may be safely used in fusion device much more data based on irradiation damage are required. The study of dislocation loops in vanadium is designed to indicate the mechanism of void growing under irradiation. The mechanism is that different types of dislocation loops have different bias which represent their abilities to absorb point defects. It is possible to explain the irradiation swelling performance in the material with the bias of loops. The thin disks samples used in this experiment are made of pure vanadium and vanadium alloy (V-4Cr-4Ti) by twin-jet electro-polishing. Electrolyte of H2SO4-CH3OH (1 : 6 by volume) at -20 ℃ is used in a current of 80～120 mA. To get a clear view of dislocation loops, the SRIM code is used to simulate the implantation of hydrogen ions into vanadium. The ion irradiation is carried out to a dose of 51016H+/cm2, at an energy of 30 keV. Microstructure observations are performed on a Tecnai G2 F20 (transmission electron microscope, TEM) at an accelerating voltage of 200 kV. The Burger's vectors and nature of the dislocation loops formed in pure vanadium by hydrogen implantation are confirmed by TEM. This experiment has focused on as many as 76 dislocation loops, lots of images are taken under different diffraction conditions from the same areas of interest. Results show that most of the dislocation loops have a Burger's vectors of 1/2111 (90%), and a few of 110. No loops with b= 100 loops can be found in this study. The nature of dislocation loops is determined by the inside-outside method. The number of the dislocation loops that can make sure of their nature is 29, and all of them are conformed to be interstitial type, their habit planes are from {110} to {112}. No vacancy type loops are found. The density and average size of dislocation loops in vanadium and vanadium alloy are also analysed. Compared with the pure vanadium, the loops in vanadium alloy of V-4Cr-Ti are formed in a smaller size and higher number density. As a future work the difference of the loops nature between pure vanadium and vanadium-based alloys should be investigated to illustrate their behaviour of irradiation swelling.

In this paper, a class of four-dimensional continuous autonomous system is studied. It has only one balance under certain conditions but it shows a complicated dynamic behavior. The equilibrium points and lyapunov exponents of the system are analyzed. The bound of this system is estimated and the expression of the bound is presented. In addition, the complete synchronization is also discussed by designing a linear controller. Finally, the corresponding numerical simulations are performed.