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Experiment on electrical parameters variation of different destruction type coals under uniaxial compression are studied. The results show that electrical parameters’ change curves of the loaded raw coal samples and briquette have a very good consistency; the consistency of dielectric constant curve and coal stress - strain curve is better than the resistivity curve. The resistivity curve of loaded coal in general is “concave” shape with the stress - strain curves, and the dielectric constant curve is “convex” shape generally. Compared to the initial electrical parameter values of the coal samples, the electrical parameter change rate of raw coal samples and briquette are generally higher than 13%, up to 165%, the electrical parameter change rate of raw coal samples is generally higher than briquette. The electrical parameter change of loaded coal and its stress have significantly coherence, electrical parameters variation of loaded coal better reflects the formation, development and transfixion of micro-fractures, and the characteristics of changes in internal structure in the failure process of coal rock. In the case of uniaxial compression, coal is dominated by electronic conductivity in the I, II phases, and ionic conductivity in III, IV phases, the dielectric constant changes of loaded coal have a close relation with its changes in the structure, cracks closure and cracked degree.

The heat exchanger element H-type finned tube has a high enhancement of heat transfer and excellent self-cleaning property and has evident effect in the boiler renovation, especially in the field of flue gas waste heat recovery. In this paper, the heat transfer and resistance characteristics of Htype finned tube are studied by the experimental system of open high-temperature wind tunnel. The effects of fin width, fin height, fin pitch and air velocity on fin efficiency, convective heat transfer coefficient and pressure drop are examined. It is found that as air velocity, fin height and fin width increase, fin efficiency decreases. Convective heat transfer coefficient is proportional to fin pitch but inversely proportional to fin height and fin width. Pressure drop increases with the increase of fin height and fin width. Then the correlations of fin efficiency, Nu and Eu are fitted. Keywords-waste heat recover; heat transfer, resistance; H-type finned tube

To efficiently assess and discriminate wild tea germplasms, inter-simple sequence repeats (ISSR) were used to determine genetic relationships among 40 wild tea plants. A total of 275 bands were generated with 15 ISSR primers, of which 274 (99.6%) were polymorphic. The mean genetic similarity coefficient, the mean Nei’s gene diversity (h) and the mean Shannon’s information index (I) of tea cultivars were 0.4180, 0.3797 and 0.5586, respectively. This suggested that the genetic diversity of wild tea trees and the genetic base were very wide. Unweighted pair group method with arithmetic mean (UPGMA) cluster analysis showed clear genetic relationships among these germplasms, and the major clusters were related to known pedigree relationships. Besides, from the bands amplified, there were three independent ways to identify the tea varieties, such as unique ISSR markers, unique band patterns and a combination of the band patterns provided by different primers. Finally, the ISSR fingerprints of 40 tea germplasms were constructed by the combination of the band patterns. This research indicated that ISSR markers were very effective in differentiating the wild tea varieties, too.Keywords: Wild tea plants, inter-simple sequence repeats (ISSR), molecular discrimination, genetic diversity

To obtain the recombinant group 2 allergen product of Dermatophagoides farinae (Der f 2), the Der f 2 gene was synthesized by RT-PCR. The full-length cDNA comprised 441 nucleotides and was 99.3% identical to the reference sequence (GenBank AB195580). The cDNA was bound to vector pET28a to construct plasmid pET28a(+)-Der f 2, which was transformed into E. coli BL21 and induced by IPTG. SDS-PAGE showed a specific band of about 14kDa in the hole cell lysate. s estiated by chroatography, about 3.86 g of the recobinant product as obtained, which conjugated with serum IgE from asthmatic children. The protein had a signal peptide of 17 amino acids. Its secondary structure comprised an alpha helix (19.86%), an extended strand (30.82%), and a random coil (49.32%). The subcellular localization of this allergen was predicted to be at mitochondria. Furthermore, its function was shown to be associated with an MD-2-related lipid-recognition (ML) domain. The results of this study provide a solid foundation for large-scale production of the allergen for clinical diagnosis and treatent of allergic disorders.Com a finalidade de obter o produto recombinante do alergeno grupo 2 do Dermatophagoides farinae (Der f2), o gene Der f2 foi sintetizado por RT-PCR. O cDNA continha 441 nucleotídeos e era idêntico em 99,3% à sequência de referência (GenBank AB195580). O cDNA foi ligado ao vetor pET28a para construir o plasmídeo pET28a(+)-Der f2, o qual foi introduzido por transformação em E. coli BL21 e induzido por IPTG. Em SDS-PAGE foi vista mia banda específica de 14 kDa no lisado celular. Conforme estimado por cromatografia, cerca de 3,86 mg do produto recombinante foi obtido, que reagia com IgE sérica de crianças asmáticas. A proteína continha um peptídeo sinal de 17 amino ácidos. Sua estrutura secundária consistia de uma alfa hélice (19,86%), uma fita estendida (30,82%), e uma sequência randômica (49,32%). A localização subcelular desse alergeno foi predita ocorrer nas mitocôndrias. Sua função foi associada com o domínio de reconhecimento lipídico (ML) relacionado a MD-2. Os resultados desse estudo permitem a produção em larga escala do alergeno para o diagnóstico clínico e tratamento das doenças alérgicas.

Cyclones have been widely used as separation devices during pneumatic conveying. The pipelines and cyclones inlet are connected by diameter change joints. The inlet cross section area is always larger than the pipeline. This results in the velocity of gas becoming lower than particle velocity when the gas-particles flow into the cyclone. The gas-solid flow in cyclones are investigated using FLUENT-EDEM method. The results show that the existence of particles had major effects on the gas flow of the cyclone within the inlet and conical separation parts. The tangential, axial, and radial velocities are only slightly changed when solid gas ratio at the same gas velocity/particle velocity ratio, while the velocities increase with the increasing of gas velocity/particle velocity ratios under the same solid gas ratio. The cyclone pressure drop decreases at a low solid gas ratio, and is maintained at an almost constant level with the high solid gas ratio. However, with the lower solid gas ratio, the particle strands are not clear, and the particle strand is found to become clearer and remained constant when the solid gas ratio is 6.42 kg/kg at the same gas velocity/particle velocity ratio. The particle strands form early with the increasing of gas velocity/particle velocity ratios at the same solid gas ratio. At the same time, the particle-wall interaction force is determined to be the main reason for the particle breakage and wall attrition. The results could potentially provide support for the development of a pressure drop theory for cyclones. Refereed/Peer-reviewed