O2 evolution and cyclic electron flow around photosystem I in long-term ground batch culture of Euglena gracilis

Based on the purpose of better exploring the function of green producers in the closed aquatic biological life support system, the condition of dynamic O₂ evolution and performance of cyclic electron flow around photosystem I (CEF-PSI) in long-term ground batch culture of Euglena gracilis were studied, the relationship between linear electron flow (LEF) and CEF-PSI was revealed, the function of CEF-PSI was investigated. Excellent consistency in O₂ evolution pattern was observed in cultures grown in both closed and open containers, O₂ evolution was strictly suppressed in phase 1, but the rate of it increased significantly in phase 2. CEF-PSI was proposed to be active during the whole course of cultivation, even in the declining phase 3, it still operated at the extent of 47–55%. It is suggested that the relationship between LEF and CEF-PSI is not only competition but also reciprocity. CEF-PSI was proposed to contribute to the considerable growth in phase 1; it was also suggested to play an important protective role against photosystem II (PSII) photoinhibition at the greatly enhanced level (approximately 80–95%) on the 2nd day. Our results in this research suggest that E. gracilis had very particular photosynthetic characteristics, the strict O₂ evolution suppression in the initial culture phase might be a special light acclimation behavior, and CEF-PSI could be an important mechanism involved in this kind of adaptation to the changeable light environment.     

A photoionization method for estimating BLR “size” in quasars

We describe an alternate way to estimate Broad Line Region (BLR) radii for type-1 AGN based on determination of physical conditions in the BLR under the assumption that the line emitting gas is photoionized by a central continuum source. We derive “diagnostic” intensity ratios involving UV lines Aliiiλ$\lambda$1860, Siiii]λ$\lambda$1892 and Civλ$\lambda$1549 which enable us to compute the ionizing photon flux, and hence BLR radius from the ionization parameter definition. We compare our estimates of BLR radii with values independently obtained from reverberation monitoring of Hβ$\beta$ and, in a few cases, of C ivλ$\lambda$1549. We analyze the interpretation of the photoionization estimates in the 4D eigenvector 1 context, and discuss in some detail the case of 3C 390.3. For this object we are able to provide not only the ionizing photon flux, but also an estimate of density and ionization parameter from the measured diagnostic ratios. We also compare black hole masses obtained from this method with values derived from widely-applied correlations between mass, line broadening and luminosity. Good agreement is found for both radius and black hole mass comparisons.     

高固含量改性双基推进剂的烤燃试验研究

采用非限定烤燃试验,测定了高固含量改性双基推进剂药柱的热爆炸临界温度,讨论了固含量与临界温度的关系及临界温度的尺度效应;通过高压热分解研究,获得了高固体含量推进剂热分解反应非等温动力学参数,探讨了固含量对临界温度的影响机理。结果表明,固含量由0％增加至50％,热爆炸临界温度由134．5℃上升到156．1℃,3 MPa压力下第一热分解峰温由201．8℃上升到206．2℃（β＝10℃／min）,表明热稳定性增加;长径比为1的GLX?4药柱临界温度与直径的对数呈线性关系。此外,随着固含量升高,热分解活化能由161．0 kJ／mol升高到181．9 kJ／mol,揭示了烤燃试验热获得的爆炸临界温度升高这一现象的高压热分解动力学理论依据。     

Multi-wavelength study of the short term TeV flaring activity from the blazar Mrk 501 observed in June 2014

In this work, we study the short term flaring activity from the high synchrotron peaked blazar Mrk 501 detected by the FACT and H.E.S.S. telescopes in the energy range 2–20 TeV during June 23–24, 2014 (MJD 56831.86–56831.94). We revisit this major TeV flare of the source in the context of near simultaneous multi-wavelength observations of $\gamma$–rays in MeV-GeV regime with Fermi-LAT, soft X-rays in 0.3–10 keV range with Swift-XRT, hard X-rays in 10–20 keV and 15–50 keV bands with MAXI and Swift-BAT respectively, UV-Optical with Swift-UVOT and 15 GHz radio with OVRO telescope. We have performed a detailed temporal and spectral analysis of the data from Fermi-LAT, Swift-XRT and Swift-UVOT during the period June 15–30, 2014 (MJD 56823–56838). Near simultaneous archival data available from Swift-BAT, MAXI and OVRO telescope along with the V-band optical polarization measurements from SPOL observatory are also used in the study of giant TeV flare of Mrk 501 detected by the FACT and H.E.S.S. telescopes. No significant change in the multi-wavelength emission from radio to high energy $\gamma$–rays during the TeV flaring activity of Mrk 501 is observed except variation in soft X-rays. The varying soft X-ray emission is found to be correlated with the $\gamma$–ray emission at TeV energies during the flaring activity of the source. The soft X-ray photon spectral index is observed to be anti-correlated with the integral flux showing harder-when-brighter behavior. An average value of 4.5$\%$ for V-band optical polarization is obtained during the above period whereas the corresponding electric vector position angle changes significantly. We have used the minimum variability timescale from the H.E.S.S. observations to estimate the Doppler factor of the emission region which is found to be consistent with the previous studies of the source.     

关于对发展航空运输产业若干政策的思考

用大量事实从不同侧面说明航空运输在国民经济中的地位日显重要,为国家的贡献逐年增大.同时分析了航空运输经济效益下降的原因,并提出一系列政策建议以推动航空运输向高层次方向发展.     

线性系统的最小解耦设计—一般情形

利用线性系统“根”的概念，研究了输出分块情形下的最小阶动态解耦设计问题，一方面利用根刻画了解耦补偿器的最小阶数，并且给出了设计最小阶补偿器的算法，另一方面获得了新的解耦判据。     

Thermal radiation from magnetized neutron stars

Surface thermal emission has been detected byROSAT from four nearby young neutron stars. Assuming black body emission, the significant pulsations of the observed light curves can be interpreted as due to large surface temperature differences produced by the effect of the crustal magnetic field on the flow of heat from the hot interior toward the cooler surface. However, the energy dependence of the modulation observed in Geminga is incompatible with blackbody emission: this effect will give us a strong constraint on models of the neutron star surface.     

对RLC串联电路中通频带与RLC参数关系的讨论——从一道习题引起的问题

讨论了RLC串联电路中通频带与RLC参数的关系,说明在设计一个RLC串联谐振电路时,在给定谐振频率,电感量和频带宽度时,上下边界频率不能只满足通频带宽度而任意假定,还应满足通频带与RLC这些参数之间关系的表达式.