Research on Electromagnetic Acoustic Emission Signal Recognition Based on Local Mean Decomposition and Least Squares Support Vector Machine

Electromagnetic acoustic emission technology is one of nondestructive testing, which can be used for defect detection of metal specimens. In this study, round and cracked metal specimens, round metal specimens, and intact metal specimens were prepared. And the electromagnetic acoustic emission signals of the three specimens were collected. In addition, the local mean decomposition(LMD), Autoregressive model(AR model) and least squares support vector machine (LSSVM) algorithms were combined to identify the eletromagnetic acoustic emission signals of round and cracked, round, and intact specimens. According to the algorithm recognition results, the recognition accuracy of can reach above 97.5%, which has a higher recognition rate compared with SVM and BP neural network. The results of the study show that the algorithm is able to identify quickly and accurately crack defect in metal specimens.

Genotype-Specific Microsatellite (SSR) Markers for the Sugarcane Germplasm from the Karst Region of Guizhou, China

Genetic variability among sugarcane genotypes from the Karst region of China was evaluated using genotype-specific microsatellite (SSR) markers. Eighteen sugarcane genotypes including 13 active cultivars and five elite QT-series clones bred locally were screened for genetic variability with 21 SSR primer pairs. All the primer pairs were highly polymorphic and amplified a total of 167 alleles with an average of eight alleles per primer pair. The average polymorphism information content (PIC) value was 0.86 with a range of 0.68 and 0.92. A UPGMA dendrogram categorized the 18 sugarcane genotypes into three major groups containing three, ten and five genotypes, respectively. No geographical affinity was observed among genotypes within the same group. Eight SSR primer pairs produced cultivar-specific alleles, of which five alleles were unique to the QT-series clones, namely, SMC334BS-165 and SMC851MS-145 in QT 08-558, mSSCIR43-229 in QT 4, SM597CS-182 in QT 08-536 and SMC7CUQ-168 in QT 06-212. The clone-specific SSR alleles will be useful in identifying elite QT-series clones for use in the sugarcane crossing programs in China.

Engineering practice and economic analysis of ozone oxidation wet denitrification technology

SO_(2)and NO emitted from coal-fired power plants have caused serious air pollution in China.In this study,a test system for NO oxidation using O_(3)is established.The basic characteristics of NO oxidation and products forms are studied.A separate test system for the combined removal of SO_(2)and NO_(x)is also established,and the absorption characteristics of NO_(x)are studied.The characteristics of NO oxidation and NO_(x)absorption were verified in a 35 t·h^(-1)industrial boiler wet combined desulfurization and denitrification project.The operating economy of ozone oxidation wet denitrification technology is analyzed.The results show that O_(3)has a high rate and strong selectivity for NO oxidation.When O_(3)is insufficient,the primary oxidation product is NO_(2).When O_(3)is present in excess,NO_(2)continues to get oxidized to N_(2)O_(5)or NO_(3).The removal efficiency of NO_(2)in alkaline absorption system is low(only about 15%).NOx removal efficiency can be improved by oxidizing NO_(x)to N_(2)O_(5)or NO_(3)by increasing ozone ratio.When the molar ratio of O_(3)/NO is 1.77,the NOx removal efficiency reaches 90.3%,while the operating cost of removing NO_(x)per kilogram is 6.06 USD(NO_(2)).

Chartrenoline, a novel alkaloid isolated from a marine Streptomyces chartreusis NA02069

A novel alkaloid, chartrenoline(1), featuring an unusual 6/6/5/5-tetracyclic nucleus, was isolated from a marine Streptomyces chartreusis NA02069. The structure of 1 including its absolute configurations was established by extensive analyses of its high resolution mass, NMR and single-crystal X-ray diffraction data. A plausible biosynthetic pathway for chartrenoline(1) is proposed.

Reduced graphene oxide wrapped hollow molybdenum trioxide nanorod for high performance lithium-ion batteries

Reduced graphene oxide wrapped hollow molybdenum trioxide nanorods （MoO3@rGO） have been fabricated by a facile process. The MoO3@rCO shows improved lithium storage performance. It could deliver a high reversible capacity （842 mAh/g at 0.1 A/g）, excellent cycling stability （778 mAh/g at 0.1 A/g after 200 cycles） and excellent rate capability （455 mAh/g at 2A/g）. The excellent electrochemical performance could be attributed as the special core （MoO3）/sheath （rCO） structure, which could accommodate the volume change of MoO3 during lithiation/delithiation process. In addition, the rGO coating layer could improve the electronic conductivity of MOO3.