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The sublevel open stoping with backfill method has recently been widely used in underground metal mines. The primary CPB stope is frequently affected by blasting in the secondary ore stope, leading to stope collapse and ore dilution, which has become a common problem and has received widespread attention. Numerical simulations are carried out in the present work, and a 1/4 numeral model consisting of a primary CPB stope and a secondary ore stope is built. The secondary ore stope is divided into four layers on average in the simulation model, and the incident stress induced by each blasting at the interface of the CPB and ore is simulated. The results show that the CPB stope in the range within the height of the explosive charge induced horizontal compressive stress and tensile stress induced from the explosive charge height, while the mined section under the charge height has no obvious blasting impact. The maximum incident compressive stress is close to 1.2 MPa and occurs in the area closest to the blast hole The maximum induced tensile stress occurs in the range above the charge height, which is about 0.2 MPa. The stress ratios of the four-layered lift blasts are 3.6%, 3.8%, 4.0%, and 4.8%, respectively, showing a slight cumulative effect of layered blasting. In addition, the positive correlation between incident stress and the stress ratio is studied in the present work, and the results show that the greater the incident stress is, the greater the incident ratio is. [ABSTRACT FROM AUTHOR]

The blasting damage test under the conditions of different bunch-holes spacing and equivalent large hole(KLH) spacing carry out in a small-scale field test. When blasting with single bunch-holes or single KLH, the damage range of side blasting of charge is larger than that of both ends, and the P wave velocity of damaged rock is lower. With the increase of the distance from the charge, the damage variable decreases exponentially, and the ELH damage variable decreases faster than that of the bunch-holes. In the near blasting area(x<5.56 Do), the damage variable of KLH is higher than that of bundle-holes. In the middle and far zone of blasting(x<5.56 Do), the damage variable of bunch-holes is higher than that of KLH. During blasting of the bunch-holes group and KLH group, the group spacing increases, and the damage variable of rock between groups decreases. Under the condition of the same spacing, the blasting damage variable of rock between bunch-holes is greater than or equal to the KLH damage variable. When the spacing of bunch-holes/KLH is 1.5 m(16.67 Do), 2.0 m(22.22 Do), the superposition damage between groups increases by 30%--40% compared with the value of the single hole damage variable. [ABSTRACT FROM AUTHOR]

An efficient Pd-catalyzed domino Mizoroki–Heck and reductive Heck reaction of terminal alkenes with six-membered cyclic diaryliodoniums is reported for the facile access to a diverse set of novel dihydroanthracenes. The scope of alkenes is general, leading to concise generation of 30 dihydroanthracenes which are not easily accessed by conventional methods. Furthermore, one of the newly synthesized dihydroanthracene displayed excellent antiproliferative activity against PANC-1 cancer cells (IC50 = 11.74 μM). [ABSTRACT FROM AUTHOR]

Starting from cyclic diaryliodoniums and terminal alkenes, a diverse set of fluorenes is conveniently constructed. The reactions catalyzed by palladium undergo one conventional Mizoroki‐Heck reaction and one reductive Heck reaction. The scope of alkenes is general, leading to 29 fluorenes which would expand the structural diversity of fluorene reservoir. [ABSTRACT FROM AUTHOR]

Selecting superior clones is the first step for commercial short‐rotation coppice cultures to provide biomass and bioenergy. Till date, such selection for hybrid Populus clones in middle China is absent. Here we describe the growth, aboveground biomass production and cell wall composition of 27 hybrid poplar clones in Henan, China for two 3‐year rotations. Significant variation in these three characteristics over two triennial rotation coppices among the 27 poplar clones was observed. During two 3‐year rotation coppices, clones '276', '02‐17', and '599' showed relatively higher tree heights and larger basal diameters than those of the other clones. However, the most productive clones were '36' and '01‐30'. At the end of the second triennial rotation, the aboveground biomass production reached 18 Mg ha−1 year−1. For the cell wall composition analysis, the cellulose contents of clones '01‐243' and '2001' were relatively high, while the xylose contents of clones '01‐30' and '65' were relatively high. Cluster analysis based on height, basal diameter, biomass, heat value, cellulose content, and survival rate revealed five growth potential classes. Accordingly, clones '03‐332', '36', and '599' exhibited high biomass and growth and had the greatest potential to serve as excellent biomass producers in Henan, China. In addition, the expression patterns of 20 key regulatory genes were analyzed, and an integrated coexpression network was constructed. This field trial provides a comprehensive quantification and evaluation of the agronomic performance of 27 poplar clones in Henan, China. The results of this study and the analytical strategies provide an efficient mechanism for selecting clones that will perform well agronomically in local environments. The expression of key genes and the integrated coexpression network provide the molecular mechanisms of poplar biomass performance. [ABSTRACT FROM AUTHOR]

Bamboo is one of the fastest growing plants in the world, but their shoot buds develop very slowly. Information about the sugar storage and metabolism during the shoot growth is lacking. In the present study, we determined the activity of sucrose and starch metabolizing enzymes during the developmental period of Fargesia yunnanensis from shoot buds to the young culms that have achieved their full height. The soluble sugars and starch contents were also determined and analyzed in shoot buds and shoots at different developmental stages. The results showed that there were higher sucrose contents in shoot buds than shoots, which coincides with the sweeter taste of shoot buds. As the shoot buds sprouted out of the ground, the starch and sucrose were depleted sharply. Coupled with this, the activity of soluble acid invertase (SAI), cell wall‐bound invertase (CWI), sucrose synthase at cleavage direction (SUSYC) and starch phosphorylase (STP) increased significantly in the rapidly elongating internodes. These enzymes dominated the rapid elongation of internodes. The activities of SAI, CWI, SUSYC and STP and adenosine diphosphate‐glucose pyrophosphorylase were higher as compared to other enzymes in the shoot buds, but were far lower than those in the developing shoots. The slow growth of shoot buds was correlated with the low activity of these enzymes. These results complement our understanding of the physiological differences between shoot buds and elongating shoots and ascertain the physiological mechanism for the rapid growth of bamboo shoots. [ABSTRACT FROM AUTHOR]