飞行人员骨密度与内分泌调节关系的探讨

对37名骨密度(BD)低下的飞行员(实验组)和BD正常的48名飞行员、100名地面人员(正常对照组)进行了BD和血清TT_3、TT_4、TSH IRMA、CT、PTH、E_2和T放射免疫测定。结果显示,实验组BD均值明显低于对照组(p<0.01),血清TT_3、TT_4、CT、E_2(女性)和T(男性)均值与对照组比较,大多数年龄存在着显著或非常显著差异(p<0.05或p<0.01)。同时对飞行人员BD与几种内分泌激素关系进行了探讨。     

裂解C_5馏分综合利用的对策

探讨了裂解C_5馏分就近集中分离综合利用和分散直接利用,以及建设单独分离双环戊二烯装置发展下游精细化工产品的综合利用策略。     

Minimum entropy and information measure

Kapur et al. (1995) introduced the MinMax information measure, which is based on both maximum and minimum entropy. The major obstacle for using this measure, in practice, is the difficulty in finding the minimum entropy. An analytical expression has already been developed for calculating the minimum entropy when only variance is specified. An analytical formula is obtained for calculating the minimum entropy when only mean is specified, and numerical examples are given for illustration     

Anomalous variations of OFF-State leakage current in poly-Si TFTunder static stress

Studies the anomalous variations of the OFF-state leakage current (I_OFF) in n-channel poly-Si thin-film transistors (TFTs) under static stress. The dominant mechanisms for the anomalous I_OFF can be attributed to (1) I_OFF increases due to channel hot electrons trapping at the gate oxide/channel interface and silicon grain boundaries and (2) I_OFF decreases due to hot holes accumulated/trapped near the channel/bottom oxide interface near the source region. Under the stress of high drain bias, serious impact ionization effect will occur to generate hot electrons and hot holes near the drain region. Some of holes will be injected into the gate oxide due to the vertical field (~(V_Gstress V_Dstress)/T _OX) near the drain and the others will be migrated from drain to source along the channel due to lateral electric field (~V_Dstress/L_CH)     

专家系统在化工中的应用进展

本文综述了近年来专家系统在化工领域的应用状况，并指出今后的发展趋势。     

Robust adaptive control of robotic manipulators without the regressor matrix

A new adaptive controller is presented here for rigid-body robotic manipulators. It is stable and robust with respect to a class of external disturbances. The robustness of the adaptive controller is established without the ‘slow-varying’ assumption and the computationally demanding regressor matrix. The control law consists of a non-adaptive PD control part and an adaptive control part. It uses two adaptive matrices to compensate two uniformly bounded coefficient matrices derived from the original dynamics. A α σ|q?|-modified adaptive law is designed to adjust the adaptive matrices. A Lyapunov-type stability analysis indicates that the closed-loop system is uniformly ultimately bounded. The tracking error and compensation error will eventually converge into a closed region, which can be made arbitrarily small by adjusting the controller parameters. Simulation results are included to demonstrate the performance of the proposed controller.     

Fluidised pellet bed bioreactor: a promising technology for onsite wastewater treatment and reuse.

A pilot-scale fluidised pellet bed (FPB) bioreactor, which combines chemical coagulation, biological degradation, particle pelletisation and separation in one unit, was applied for onsite wastewater treatment and reuse. As a result of rational use of inorganic coagulant and organic polymer and moderate mechanical agitation, spherical particles were generated in the upflow column and a well-fluidised bed was formed. With a continuous supply of dissolved oxygen through a recycling loop, an aerobic condition was kept in the bottom section of the FPB column. Under such conditions the pellets in the FPB column showed the following characteristics: (1) compact structure and high density; (2) rich in microorganisms; and (3) high MLSS and MLVSS concentrations. Therefore, the FPB bioreactor achieved more than 90% removal of SS, COD, BOD and TP from raw domestic wastewater within a total hydraulic retention time (HRT) of only about 30 minutes. It also showed nitrification and denitrification ability and the TN removal could be about 50% as the recycling ratio was increased to 1:1. The treated water quality is generally competitive with the secondary effluent from a conventional activated sludge process. With these advantages the FPB bioreactor is recommendable as a compact system for onsite wastewater treatment and reuse.     

Effect of supports on the redox performance of pyrite cinder in chemical looping combustion

Chemical looping combustion (CLC) is a clean and efficient flame-free combustion technology,which combust the fuels by lattice oxygen from a solid oxygen carrier with inherent CO2 capture.The develop-ment of oxygen carriers with low cost and high redox performance is crucial to the whole efficiency of CLC process.As the solid by-product from the sulfuric acid production,pyrite cinder presented excellent redox performance as an oxygen carrier in CLC process.The main components in pyrite cinder are Fe2O3,CaSO4,Al2O3 and SiO2 in which Fe2O3 is the active component to provide lattice oxygen.In order to sys-tematic investigate the functions of supports (CaSO4,Al2O3 and SiO2) in pyrite cinder,three oxygen car-riers (Fe2O3-CaSO4,Fe2O3-Al2O3 and Fe2O3-SiO2) were prepared and evaluated in this study.The results showed that Fe2O3-CaSO4 displayed high redox activity and cycling stability in the multiple redox cycles.However,both Fe2O3-Al2O3 and Fe2O3-SiO2 experienced serious deactivation during redox reactions.It indicated that the inert Fe-Si solid solution (Fe2SiO4) was formed in the spent Fe2O3-SiO2 sample,which decreased the oxygen carrying capacity of this sample.The XPS results showed that the oxygen species on the surface of Fe2O3-CaSO4 could be fully recovered after the 20 redox cycles.It can be concluded that CaSO4 is the key to the high redox activity and cycling stability of pyrite cinder.     

细胞激动素Kinetin合成的改进

介绍了用糠胺与腺嘌呤在催化条件下反应合成细胞激动素kinetin,该法原料易得,反应条件温和,产品收率及纯度都较高。     

气化炉复合炉衬的传热计算

新型 (多喷嘴对置 )水煤浆气化炉拟采用水冷管和耐火浇铸料组成的复合炉衬结构 .炉内的高温高压对复合炉衬的高温侵蚀十分严重 ,是影响其寿命的重要因素 ,因此合理设计气化炉复合炉衬的结构对充分发挥其材质的作用具有十分重要的意义 .建立了气化炉复合炉衬的传热计算的数学模型 ,同时编制了模型求解的计算程序 ,并用某工艺条件对复合炉衬的温度分布进行了计算 .结果表明 ,该方法可有效计算出复合炉衬的温度分布情况 ,为复合炉衬的设计、运行和维护提供理论依据