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Faced with the severe eco-environmental problems and economic slowdown, China started the exploration of public-private partnership mode on eco-environmental protection projects, aiming to solve the disbalance between environmental improvement and investment shortage. This study systematically analyzed the characteristics, policy and market reactions of eco-environmental protection public-private partnership projects since 2014. Till the end of 2018 in China, the number of eco-environmental protection public-private partnership projects was 2,914 and investment was 1.84 trillion RMB, accounting for 33.67% and 13.94% of the total, respectively. The peak year was in 2017, then the number of eco-environmental protection public-private partnership projects dropped significantly in 2018. It is estimated that from 2014 to 2018, the investment from eco-environmental protection public-private partnership projects in the implementation phase contributes to 3.2% of China's GDP, 0.2 % of economic growth. To some extent, it has accelerated the process of ecological and environmental governance in China, especially in the field of municipal environmental infrastructure construction and comprehensive environmental treatment. However, the expected effect of eco-environment improvement from eco-environmental protection public-private partnership projects is difficult to guarantee, with the absence of key mechanisms and policies.

In order to study the effect of foliar DA-6 on the phosphorus and potassium content of tomato seedlings under cadmium stress, the pot experiment was used to cultivate ‘Zhongza 9’ tomato in 50 μmol/L CdCl2•2.5H2O nutrient solution. The effects of DA-6 at different concentrations (0, 10, 20, 30 and 40 mg/L) on the phosphorus and potassium uptakes of tomato seedlings under cadmium stress were studied. The results showed that when the DA-6 concentration was 20 mg/L, the phosphorus content in the root and stem of tomato seedlings increased significantly, which were 41.5% and 12.8% higher than the control. In all treatments, when the DA-6 concentration was 10 mg/L, the potassium content of tomato seedling roots, stems and shoots increased significantly, which were 25.4%, 10.0%, and 5.8% higher than the control. In summary, the low-concentration DA-6 treatment had a certain effect on increasing the phosphorus and potassium content of tomato, and there were differences in the optimal concentration of phosphorus and potassium content.

Among the putative mechanisms, by which extremely low frequency magnetic field (ELF-MF) modify calcium metabolism is that of affecting Ca2+ fluxes across cell membrane or internal Ca2+ stores. To test this hypothesis, whether ELF MF can modulate Ca2+ fluxes of isolated skeletal muscle sarcoplasmic reticulum vesicles (SR) was investigated in the present study. The Ca2+ transport and Ca2+-Mg2+-ATPase activity were observed by means of dynamic Ca2+ dye spectrum, the function of ryanodine receptor (RyR1) was monitored by [3H]-ryanodine binding assay. The membrane fluidity of SR was measured by fluorescence polarization. 50 Hz 0.4 mT MF exposure for 30 min led to a significant decrease in the Ca2+ uptake initial rate and Ca2+-Mg2+-ATPase activity compared to sham exposed SR. These results strongly suggest that prevention of SR Ca2+ uptake by ELF MF exposure was due to the inhibition of Ca2+-Mg2+- ATPase activity, and the increase of SR Ca2+ release was due to the activation of RyR1.

In plant growth and stress tolerance, indole-3-acetic acid (IAA) plays an important role. In this research, the effects of spraying different concentration (0, 25, 50, 100 and 200 μmol/ L) of IAA on the antioxidant system in lettuce were investigated. The lettuce (Lactuca sativa) exposed to cadmium (Cd) exhibited the SOD, POD activities and MDA content obviously increased. Spraying exogenous IAA resulted that the CAT activity, soluble protein and proline content in shoots of lettuce increased compared with the Cd treatment alone, and MDA content with 50 μmol/L IAA was lowest. Therefore, spraying IAA effectively alleviated Cd toxicity and enhanced antioxidant system of lettuce, and the 100 μmol/L IAA was the optimal dose.

Indole-3-acetic acid (IAA) plays crucial roles in plant growth and stress tolerance. In present study, the effects of spraying different concentrations (0, 25, 50, 100 and 200 μmol/L) of IAA on the growth and cadmium (Cd) accumulation in lettuce (Lactuca sativa) were investigated. The lettuce exposed to Cd exhibited a substantial decline in growth, and the Cd content of them significantly increased. Spraying exogenous IAA resulted in alleviating the inhibitory of Cd toxicity to lettuce. The dry weight in shoots of lettuce increased by spraying with IAA compared with the Cd treatment alone, but the dry weight of roots had no significantly differences. Although exogenous IAA increased the root Cd content, it significantly reduced shoot Cd content, indicating its role in Cd transport. Therefore, spraying IAA effectively alleviated Cd toxicity and reduced Cd uptake in the edible parts of lettuce, and the 100 μmol/L IAA was the optimal dose.

The thermal deformation microstructure of continuous extrusion copper bus bar was observed and analyzed in the temperature range from 200°C to 700°C and at strain rate from 0.01s-1 to 10.0s-1 and at deformation amount from30% to 90% on Gleeble1500 test machine. The experiment results show that the higher the temperature, the lower the strain rate, the more dynamic recrystallization occurred. At the same strain rate, the copper bus bar changes from raw material of as-cast organization to recrystallization grain gradually as the deformation temperature and deformation degree increase, and the recrystallization grain size grows older with the rise of temperature. At the same deformation temperature, the temperature of recrystallization nucleation decreases while the strain rate increases. At low strain rate (0.01~1.0s-1), the dynamic recrystallization occurred at 500°C. While at high strain rate (10.0s-1), the recrystallization nucleation is advanced and it is already completed at 500°C. The Z parameters can be used to express the effect of deformation temperature and strain rate on the average grain size D, and the prediction model of the thermal deformation microstructure is obtained as follows: lnD=4.822-0.018lnZ

High-technology enterprises play the leader role in the regional economic progress, but nowadays technological resources have many problems such as division, separation and dispersing. It’s an urgent problem to be solved that how to evaluate input-output productivity of technological resources towards industries and regions scientifically and efficiently. Firstly the article analyzes the input-output efficiency status of technological resources at home and abroad. Then high-technology enterprises in 29 provinces, as the subject of evaluation, are analyzed for their operation efficiency by DEA. The article states the suggestions like balanced development among regions and reasonable structure of input and output by comparing the differences among regions. And the article estimates the technological resources configuration efficiency of 5 leader industries and explains the developmental characteristics and direction among industries. And on these bases the article conducts hypothesis testing for inner elements which might have an influence on the operational efficiency by Tobit model. Finally, the paper proposes many suggestions to the benefits of promoting the productivity of high-technology enterprise according to the comprehensive analysis.

Recently, more and more authors have been encouraged for collaboration because it often produces good results. However, the author collaboration network contains experts in various research directions within various fields, and it is difficult for individual authors to decide which authors are best suited to their expertise. This paper uses the relationships among authors to predict new relationships that may arise, recommending each author with the collaborators they may be interested in. The data source comes from 4-year data in DBLP from 2001 to 2004. After data cleaning, the training set and test set are constructed and then used BP neural network to build model. At the same time, this article compares the performance with Logistic Regression, SVM and Random Forest. The experiment shows that the BP neural network can get better result, and it is feasible to predict links in the author collaboration network.