Excavation of the tunnel in high geo-stress environment induces strong stress redistribution, resulting in unloading damage of surrounding rock. The damaged surrounding rock is the main load bearing body for the tunnel in the running period. Therefore, it is necessary to study the acoustic emission (AE) characteristics during the reloading of damaged rock. The marble was chosen to manufacture specimens in this paper, and we designed pre-peak unloading tests. Confining pressure of pre-peak unloading test is 15MPa and three types of unloading point (70MPa, 80MPa and 90MPa). The laboratory tests are made for studying AE characteristics of damaged marble samples by using MTS816 and acoustic emission instrument AE21C. The test results showed that as the unloading point increases, the peak strength of the rock decreases with increased corresponding peak strain. Rock failure mode gradually changed from brittle failure to quasi-brittle failure; Accumulated AE count is negatively correlated with the unloading point, and the AE quiet period is positively correlated with the unloading point. The evolution of b -value is divided into three phases: slow increase, sharp increase and rapid decrease. The findings of this research can provide the significance for selecting mechanical parameters of the surrounding rock and optimizing support scheme.

In order to reduce the adverse impact of electric vehicles (EVs) charging load on the grid and guide users to participate in the grid interaction reasonably and effectively, an coordinated charging and discharging control model of EVs based on the two dimensions of time and space is established in this paper to meet the dynamic and economic needs of users' coordinated charging and discharging. Considering the space-time distribution characteristics of EVs, the model is decoupled into an optimal scheduling sub-model based on time and space scale, and the model is solved by genetic algorithm and power flow calculation. The example shows that the model can effectively reduce the peak-to-valley difference, achieve the effect of peak-cutting and valley-filling, and the dual optimization goals of optimizing the operation of the system and encouraging users to participate in V2G are achieved.

As an important resource for human survival, soil plays an important role in maintaining productivity, environmental quality, animal and plant health, etc. Unreasonable use of land resources and large-scale soil degradation has brought serious threat to human beings. At present, the evaluation of soil quality focuses on the physical and chemical properties of soil, and the study of soil microorganisms has little impact on soil quality. This paper attempts to construct a new soil quality evaluation system from the perspective of soil microorganisms, highlighting the important role of soil microorganisms, and providing new ideas for the rational construction of soil quality evaluation system.

Chinese cherry [ Cerasus pseudocerasus (Lindl). G. Don] is a commercially valuable fruit crop in China. Although Chinese cherry has a long cultivation history in Luding County, the cultivation status and utilization still remain at the early stage. In this study, we investigated the cultivation status and evaluated the economic traits of Chinese cherry germplasms distributed in 39 villages of 12 towns in Luding County. Chinese cherry is widely situated in variable habitats with various topographies and landforms for its great adaptability. All the County plants Chinese cherry for more than 160000 trees with the yield over 6000 t per year. Lengqi, Luqiao, Pengba, Tianba and Wuni towns have relatively higher field yields and higher income than other towns. A large number of Chinese cherry genetic resources are in danger because of the road development, environment destroying and replacement by sweet cherry. The phenological period lasts for nearly 3 to 4 months from infancy to red mature fruits for Luding cherry. The fruit size ranges from 12.14 mm / 14.73 mm to 17.51 mm / 19.11 mm (longitudinal / transverse diameter) with the fruit shape index from 0.80 to 0.92, revealing nearly spherical shape. The weight per fruit ranges from 1.91 to 3.61 g, corresponding to the germplasms of Nanmenguan Yanzigou and Machang Pengba. The total soluble solid content is over 14% among 12 Luding Chinese cherry resources with the maximum value of 18.8%. Vitamin C and total sugar content ranges from 4.03 to 8.75 mg·100mL −1 , and from 7.82 to 13.82 g·100mL −1 , respectively. By comprehensive evaluation, Chinese cherry germplasms from Wuni and Machang villages show the most excellent economic traits, which can be further developed and utilized in the future. The transverse diameter, weight per fruit, and total acid content reveal significant positive correlation with altitude, while fruit shape index and sugar accumulation is negatively correlated to altitude. In addition, Luding Chinese cherry reveal some advantages compared with other areas in Sichuan Basin so that effective measures should be taken to preserve these valuable resources and utilize them for cherry breeding program in the future.

The protection of traditional villages plays an important role in the strategy of inheriting Chinese outstanding history and culture, and it is also an important type for the transformation and development of traditional farming civilization to modern ecological civilization. In this paper, it is held that, currently, traditional village transformation and development follow the laws of policy orientation attracting capital intervention, capital intervention promoting village development, and village development supporting policy orientation in turn with actual internal forces, realizing a ternary integrated development path for the country, market, and village. Based on the logic inference and deduction on the three-dimensional path driven by departmental policy capital, urban industrial and commercial capital as well as rural community and owned capital, a series of typical cases of Chongqing are selected for demonstration. Studies show: (1) At this stage, traditional village transformation and development will inevitably be driven by both internal and external forces, since the driving power of one single force is limited. Only by conforming to external driving forces such as policies and capital and internal endowments of village resources, culture and economic foundation, can the predicament in traditional village transformation and development be overcome; (2) The key to realizing rural transformation and development lies in stimulating internal driving forces of villages. Economic reconstruction with industry cultivation as its core is the most active factor in rural development, and it plays a leading role in social and landscape reconstruction; (3) Historical rural landscape is an important resource for the transformation and development of villages. Therefore, both macro policies and regulations and capital intervention should be based on a full understanding of the value of historical landscape, and a thorough and true cognition and evaluation on the composition and characteristics of historical landscape.

Cherry ( Cerasus Mill.) species are important agricultural crops with high economic and ornamental values. The seeds of stone fruits have a long dormancy period after harvest, which cannot germinate and grow until the dormancy has been broken. In order to break the dormancy and speed up the gremination of cherry seeds, we studuied the effect of GA3 treatment on the dormancy-breaking and germination rate of Chinese cherry and sweet cherry seeds without cold stratification. The results showed that GA 3 treatment significantly increased the germination rates of cherry seeds, reaching the maximum value of 64%, 24% and 40% at the concentration of 100 mg•L −1 of GA 3 for cultivated and wild Chinese cherry, and sweet cherry. In addition, GA 3 treatment obviously speed up the germination index of cherry seeds, reaching the maximum value when immersing seeds with 100 mg•L −1 of GA 3 . Therefore, it is necessary to cultivate cherry seedlings by GA 3 treatment.