Hydraulic supports for polishing TMT M3MP

For polishing the ultra-thin TMT M3MP, a polishing support system with 18 hydraulic supports (HS) is introduced. This work focuses on the designing and testing of these HSs. Firstly the design concept of HS system is discussed; then mechanical implementation of the HS structure is carried out, with special consideration of fluid cycling, work pressurization and the weight component. Afterward the piping installation and the de-gas process for the working fluid are implemented. Pressurization and stiffness are well checked before system integration for the single HS unit. Finally the support system is integrated for the polishing process

The Application of Pentaprism Scanning Technology on the Manufacturing of M3MP

The PSS (pentaprism scanning system) has advantages of simple structure, needless of reference flat, be able of on-site testing, etc, it plays an important role in large flat reflective mirror’s manufacturing, especially the high accuracy testing of low order aberrations. The PSS system measures directly the slope information of the tested flat surface. Aimed at the unique requirement of M3MP, which is the prototype mirror of the tertiary mirror in TMT (Thirty Meter Telescope) project, this paper analyzed the slope distribution of low order aberrations, power and astigmatism, which is very important in the manufacturing process of M3MP. Then the sample route lines of PSS are reorganized and new data process algorism is implemented. All this work is done to improve PSS’s measure sensitivity of power and astigmatism, for guiding the manufacturing process of M3MP

miR-181a increases FoxO1 acetylation and promotes granulosa cell apoptosis via SIRT1 downregulation.

Oxidative stress impairs follicular development by inducing granulosa cell (GC) apoptosis, which involves enhancement of the transcriptional activity of the pro-apoptotic factor Forkhead box O1 (FoxO1). However, the mechanism by which oxidative stress promotes FoxO1 activity is still unclear. Here, we found that miR-181a was upregulated in hydrogen peroxide (

Edge control in a computer controlled optical surfacing process using a heterocercal tool influence function

Edge effect is regarded as one of the most difficult technical issues in a computer controlled optical surfacing (CCOS) process. Traditional opticians have to even up the consequences of the two following cases. Operating CCOS in a large overhang condition affects the accuracy of material removal, while in a small overhang condition, it achieves a more accurate performance, but leaves a narrow rolled-up edge, which takes time and effort to remove. In order to control the edge residuals in the latter case, we present a new concept of the ‘heterocercal’ tool influence function (TIF). Generated from compound motion equipment, this type of TIF can ‘transfer’ the material removal from the inner place to the edge, meanwhile maintaining the high accuracy and efficiency of CCOS. We call it the ‘heterocercal’ TIF, because of the inspiration from the heterocercal tails of sharks, whose upper lobe provides most of the explosive power. The heterocercal TIF was theoretically analyzed, and physically realized in CCOS facilities. Experimental and simulation results showed good agreement. It enables significant control of the edge effect and convergence of entire surface errors in large tool-to-mirror size-ratio conditions. This improvement will largely help manufacturing efficiency in some extremely large optical system projects, like the tertiary mirror of the Thirty Meter Telescope

Hydraulic supports for polishing TMT M3MP

For polishing the ultra-thin TMT M3MP, a polishing support system with 18 hydraulic supports (HS) is introduced. This work focuses on the designing and testing of these HSs. Firstly the design concept of HS system is discussed; then mechanical implementation of the HS structure is carried out, with special consideration of fluid cycling, work pressurization and the weight component. Afterward the piping installation and the de-gas process for the working fluid are implemented. Pressurization and stiffness are well checked before system integration for the single HS unit. Finally the support system is integrated for the polishing process

Edge control in a computer controlled optical surfacing process using a heterocercal tool influence function

Edge effect is regarded as one of the most difficult technical issues in a computer controlled optical surfacing (CCOS) process. Traditional opticians have to even up the consequences of the two following cases. Operating CCOS in a large overhang condition affects the accuracy of material removal, while in a small overhang condition, it achieves a more accurate performance, but leaves a narrow rolled-up edge, which takes time and effort to remove. In order to control the edge residuals in the latter case, we present a new concept of the ‘heterocercal’ tool influence function (TIF). Generated from compound motion equipment, this type of TIF can ‘transfer’ the material removal from the inner place to the edge, meanwhile maintaining the high accuracy and efficiency of CCOS. We call it the ‘heterocercal’ TIF, because of the inspiration from the heterocercal tails of sharks, whose upper lobe provides most of the explosive power. The heterocercal TIF was theoretically analyzed, and physically realized in CCOS facilities. Experimental and simulation results showed good agreement. It enables significant control of the edge effect and convergence of entire surface errors in large tool-to-mirror size-ratio conditions. This improvement will largely help manufacturing efficiency in some extremely large optical system projects, like the tertiary mirror of the Thirty Meter Telescope

Study on chemical characteristics and evolution law of groundwater in Taigemiao Mining Area

Taigemiao Mining Area is rich in coal resources, but water resources are scarce and the ecological environment is fragile, and the use of hydrogeochemical methods to carry out research on the chemical characteristics and evolution law of groundwater in the whole basin of mining areas can provide scientific support for green mining in mining areas. Piper three-line diagram was used to analyze the types of Cretaceous groundwater, Jurassic groundwater, river water and lake water, and the water chemical characteristics met the characteristics of lake water mixed by river water and evolving groundwater; through Gibbs diagram analysis, it is concluded that the Cretaceous and Jurassic groundwater in the cyclic evolution process It is controlled by rock and evaporation; the ion ratio endmember method further shows that the Cretaceous and Jurassic groundwater is dominated by silicate rock salt and rock salt, accompanied by ion exchange; finally, the mass balance simulation shows that the Cretaceous groundwater circulation During the evolution process, dolomite, gypsum, and rock salt minerals are dissolved, CO2 is absorbed, and calcite is precipitated. With ion exchange, it can be mixed with different proportions of river water to form lake water, but Jurassic groundwater can only be mixed with a small amount of river water or not mixed with river water. The river water accounts for 83% of the water supply of Hongjiannao Lake. Jurassic groundwater cannot be the main source of water supply. The main sources of water in Hongjiannao Lake are Cretaceous groundwater and river water. Combined with the hydrogeological conditions of the mining area, the groundwater flow system of the mining area is divided into the Cretaceous groundwater flow system in the south, the Cretaceous groundwater flow system in the north and the Jurassic groundwater flow system in the deep. Coal mining directly affects the Jurassic groundwater flow system. On the premise of ensuring that the two Cretaceous groundwater flow systems are not damaged, when coal mining drainage only captures the outflow water from the Jurassic boundary or a small amount of Jurassic replenishment to Hongjiannao, coal mining will affect Hongjiannao and surrounding rivers. impact is minimized

Experimental evaluation of ensemble classifiers for imbalance in Big Data

Datasets are growing in size and complexity at a pace never seen before, forming ever larger datasets known as Big Data. A common problem for classification, especially in Big Data, is that the numerous examples of the different classes might not be balanced. Some decades ago, imbalanced classification was therefore introduced, to correct the tendency of classifiers that show bias in favor of the majority class and that ignore the minority one. To date, although the number of imbalanced classification methods have increased, they continue to focus on normal-sized datasets and not on the new reality of Big Data. In this paper, in-depth experimentation with ensemble classifiers is conducted in the context of imbalanced Big Data classification, using two popular ensemble families (Bagging and Boosting) and different resampling methods. All the experimentation was launched in Spark clusters, comparing ensemble performance and execution times with statistical test results, including the newest ones based on the Bayesian approach. One very interesting conclusion from the study was that simpler methods applied to unbalanced datasets in the context of Big Data provided better results than complex methods. The additional complexity of some of the sophisticated methods, which appear necessary to process and to reduce imbalance in normal-sized datasets were not effective for imbalanced Big Data.“la Caixa” Foundation, Spain, under agreement LCF/PR/PR18/51130007. This work was supported by the Junta de Castilla y León, Spain under project BU055P20 (JCyL/FEDER, UE) co-financed through European Union FEDER funds, and by the Consejería de Educación of the Junta de Castilla y León and the European Social Fund, Spain through a pre-doctoral grant (EDU/1100/2017)