X-群中几种广义幂零性的等价性

本文通过对任意群G的K-根K(G)的性质的研究,证明了X-群中几种常见的广义幂零性的等价性。

有限群超可解性的若干充分条件

引入弱半正规子群的概念，给出了超可解群、ｘ－群、ＣＬＴ－群等一系列问题的刻划．从而解决了满足置换条件的超可解性问题及ＱＣＬＴ－群的超可解性问题．

Study on the extra X chromosome＇s effect on the hormone level of Klinefelter＇s syndrome

Klinefelter＇s syndrome is an inherited （genetic） disorder found only in men caused by at least one extra X chromosome in a cell. Does the extra X chromosome have any effect on the hormone level of Klinefelter＇s Syndrome？ In this paper, 25 subjects with Klinefelter＇s syndrome, 30 infertile subjects and 36 normal men without Klinefelter＇s syndrome were compared each other in endocrinology profile and cytogenetics. Subjects with Klinefelter＇s syndrome were identified by the karyotypes 47, XXY or 47, XXY/46XY, and positive of the X-chromatins （Barr bodies）. Hormone analysis of subjects with Klinefelter＇s syndrome showed that the testosterone （T） values were lower than those of the normal subjects, while the FSH and LH values were higher than those of the normal people; in the infertile experiment subjects without Klinefelter＇s Syndrome, the karyotypes are 46, XY, with negative of the X-chromatins. The testosterone （T） values of these subjects were also lower than those of the normal people, but the FSH and LH values were within the normal range. These results indicated that endocrinological test on infertile subjects can be used to determine whether a cytogenetic analysis is necessary, and hence exclude non- Klinefelter＇s syndrome. The mechanism of the occurrence of this difference, its clinical applications and the relationship among the karyotypes, the endocrinological test and the severity of the phenotype are discussed. Lyon＇s hypothesis stating that only one of the two X-chromosomes is genetically active in female cells, but our study concluded that the extra X chromosome do have effect on the hormone level of Klinefelter＇s Syndrome.

Collaborative optimization of exhaust gas recirculation and Miller cycle of two-stage turbocharged marine diesel engines based on particle swarm optimization

To meet increasingly stringent emission standards and lower the brake-specific fuel consumption(BSFC)of marine engines,a collaborative optimization study of exhaust gas recirculation(EGR)and a Miller cycle coupled turbocharging system was carried out.In this study,a one-dimensional numerical model of the EGR,Miller cycle,and adjustable two-stage turbocharged engine based on WeiChai 6170 marine diesel engine was established.The particle swarm optimization algorithm was used to achieve multi-input and multi-objective comprehensive optimization,and the effects of EGR-coupled Miller regulation and high-pressure turbine bypass regulation on NO_(x)and BSFC were investigated.The results showed that a medium EGR rate-coupled medium Miller degree was better for the comprehensive optimization of NO_(x)and BSFC.At medium EGR rate and low turbine bypass rates,NO_(x)and BSFC were relatively balanced and acceptable.Finally,an optimal steady-state control strategy under full loads was proposed.With an increase in loads,the optimized turbine bypass rate and Miller degree gradually increased.Compared with the EGRonly system,the optimal system of EGR and Miller cycle coupled turbine bypass reduced NO_(x)by 0.87 g/(kW·h)and BSFC by 17.19 g/(kW·h)at 100%load.Therefore,the EGR and Miller cycle coupled adjustable two-stage turbocharging achieves NO_(x)and BSFC optimization under full loads.

Influence of Hyperon-Hyperon Interaction on Properties of Hadronic Star

The influences of hyperon-hyperon interaction on the overall properties of hadronic star are investigated in the framework of relativistic mean field （RMF） theory. For certain hyperon coupling, the weaker hyperon-hyperon interaction can lead to the heavier hadronic star, which accords with the observation of heavy neutron star in X-ray binaries. We find that the threshold densities of the hyperons with larger masses are brought to a lower values with the increase of the hyperon-hyperon interaction. The possibility of the existence of hyperon star is checked with the consideration of hyperon-hyperon interaction.

Comparative study of low NO_(x) combustion optimization of a coal-fired utility boiler based on OBLPSO and GOBLPSO

To reduce NO_(x) emissions of coal-fired power plant boilers,this study introduced particle swarm optimization employing opposition-based learning(OBLPSO)and particle swarm optimization employing generalized opposition-based learning(GOBLPSO)to a low NO_(x) combustion optimization area.Thermal adjustment tests under different ground conditions,variable oxygen conditions,variable operation modes of coal pulverizer conditions,and variable first air pressure conditions were carried out on a 660 MW boiler to obtain samples of combustion optimization.The adaptability of PSO,differential evolution algorithm(DE),OBLPSO,and GOBLPSO was compared and analyzed.Results of 51 times independently optimized experiments show that PSO is better than DE,while the performance of the GOBLPSO algorithm is generally better than that of the PSO and OBLPSO.The median-optimized NO_(x) emission by GOBLPSO is up to 15.8 mg/m^(3) lower than that obtained by PSO.The generalized opposition-based learning can effectively utilize the information of the current search space and enhance the adaptability of PSO to the low NO_(x) combustion optimization of the studied boiler.