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991.
992.
Understanding effects of ionisation in the lower atmosphere is a new interdisciplinary area, crossing the traditionally distinct scientific boundaries between astro-particle and atmospheric physics and also requiring understanding of both heliospheric and magnetospheric influences on cosmic rays. Following the paper of Erlykin et al. (2014) we develop further the interpretation of our observed changes in long-wave (LW) radiation, Aplin and Lockwood (2013) by taking account of both cosmic ray ionisation yields and atmospheric radiative transfer. To demonstrate this, we show that the thermal structure of the whole atmosphere needs to be considered along with the vertical profile of ionisation. Allowing for, in particular, ionisation by all components of a cosmic ray shower and not just by the muons, reveals that the effect we have detected is certainly not inconsistent with laboratory observations of the LW absorption cross section. The analysis presented here, although very different from that of Erlykin et al., does come to the same conclusion that the events detected by AL were not caused by individual cosmic ray primaries – not because it is impossible on energetic grounds, but because events of the required energy are too infrequent for the 12 h−1 rate at which they were seen by the AL experiment. The present paper numerically models the effect of three different scenario changes to the primary GCR spectrum which all reproduce the required magnitude of the effect observed by AL. However, they cannot solely explain the observed delay in the peak effect which, if confirmed, would appear to open up a whole new and interesting area in the study of water oligomers and their effects on LW radiation. We argue that a technical artefact in the AL experiment is highly unlikely and that our initial observations merit both a wide-ranging follow-up experiment and more rigorous, self-consistent, three-dimensional radiative transfer modelling. 相似文献
994.
We evaluated the effects of ultraviolet-B(UV-B) radiation and different light conditions on the repair of UV-B-induced damage in carpospores of C hondrus ocellatus Holm(Rhodophyta) in laboratory experiments. Carpospores were treated daily with different doses of UV-B radiation for 48 days,when vertical branches had formed in all treatments; after each daily treatment,the carpospores were subjected to photosynthetically active radiation(PAR),darkness,red light,or blue light during a 2-h repair stage. Carpospore diameters were measured every 4 days. We measured the growth and cellular contents of cyclobutane pyrimidine dimers(CPDs),chlorophyll a,phycoerythrin,and UV-B-absorbing mycosporine-like amino acids(MAAs) in carpospores on Day 48. Low doses of UV-B radiation(36 and 72 J/m 2) accelerated the growth of C. ocellatus. However,as the amount of UV-B radiation increased,the growth rate decreased and morphological changes occurred. UV-B radiation significant damaged DNA and photosynthetic pigments and induced three kind of MAAs,palythine,asterina-330,and shinorine. PAR conditions were best for repairing UV-B-induced damage. Darkness promoted the activity of the DNA darkrepair mechanism. Red light enhanced phycoerythrin synthesis but inhibited light repair of DNA. Although blue light,increased the activity of DNA photolyase,greatly improving remediation efficiency,the growth and development of C. ocellatus carpospores were slower than in other light treatments. 相似文献
995.
联合使用位模型和地形信息的陆区航空重力向下延拓方法 总被引:1,自引:0,他引:1
为了规避传统逆Poisson积分向下延拓解算过程的不适定性问题,借鉴导航定位中的"差分"概念,利用超高阶位模型直接计算海域航空重力测量向下延拓改正数的方法。本文在此基础上提出联合使用重力位模型和地形高数据,计算陆部航空重力向下延拓总改正数的改进方案,以飞行高度面与地面对应点的位模型差分信息表征总改正数的中长波分量,以相对应的局部地形改正差分修正量表征总改正数的中高频成分,从而实现航空重力数据点对点向地面的全频段延拓。在地形变化不同区域,联合使用EGM2008位模型、地面实测重力和高分辨率高程数据进行了实际数值计算和精度评估,验证了该方法的有效性。 相似文献
996.
卫星导航服务的全球电离层时变特性分析 总被引:2,自引:0,他引:2
针对电离层对无线电波应用技术的影响,该文利用IGS提供的1998年—2012年的全球电离层TEC数据,结合相应的太阳活动数据,采用时间序列分析、相关性分析以及等值线图等数理统计的方法,分析了全球电离层的时变特性;分析了电离层TEC、F10.7和太阳黑子数的相关性,发现3者之间的相关系数高度线性相关。通过电离层日变化规律的研究发现:电离层TEC日极大值出现的时刻集中在当地时间12时至16时,其中14时占38.47%,12时占26.58%,16时占19.05%;夜间TEC值与太阳活动强度密切相关,在太阳活动低峰年,夜间全球电离层TEC平均值在5TECU左右,在太阳活动高峰年,夜间全球电离层TEC平均值在17TECU左右,最大值可达24TECU。最后,从日地距离和太阳活动强度两个方面,讨论了全球电离层TEC季节变化规律以及成因。 相似文献
997.
998.
Using Damour-Ruffini’s and Hamilton-Jacobi’s methods, Hawking radiation from a Vaidya black hole is investigated. Due to non-stationary
black holes, the event horizon r
H
and the entropy S are all related to both the mass m(υ) and
. When the back-reaction of particles’s energy to space-time is considered, we get the emission probability. It is found that
the result is different from that of the stationary Schwarzschild black hole, because
is the function of mass m(υ).
相似文献
999.
We analyze the pulses in high-frequency drift radio structures observed by the spectrometer at Purple Mountain Observatory
(PMO) over the frequency range of 4.5 – 7.5 GHz during the 18 March 2003 solar flare. A number of individual pulses are determined
from the drifting radio structures after the detected gradual component subtraction. The frequency distributions of microwave
pulse occurrence as functions of peak flux, duration, bandwidth, and time interval between two adjacent pulses exhibit a power-law
behavior, i.e.
. From regression fitting in log-log space, we obtain the power-law indexes, α
P=7.38±0.40 for the peak flux, α
D=5.39±0.86 for the duration, and α
B=6.35±0.56 for the bandwidth. We find that the frequency distribution for the time interval displays a broken power law. The
break occurs at about 500 ms, and their indexes are α
W1=1.56±0.08 and α
W2=3.19±0.12, respectively. Our results are consistent with the previous findings of hard X-ray pulses, type III bursts, and
decimetric millisecond spikes. 相似文献
1000.
In this work, we shall confine ourselves to solve analytically the integrals called
,
for the two components of albedo radiation pressure on an Earth’s satellite. When the Earth’s albedo is variable, as far as
we know, this case has not been dealt with analytically. We shall solve these two integrals when the satellite’ horizon is
illuminated and when the sun lies on the equator. This approach will facilitate the evaluation of the mentioned two equations.
We will also compare our results with previous works obtained numerically. 相似文献