玻璃温室内植物层中总辐射分布规律

在对上海地区荷兰玻璃温室中黄瓜植物层内进行总辐射观测的基础上，研究秋、冬、春末夏初三个季节内晴天、阴天温室中黄瓜植物层内总辐 射的分布规律。     

云层与气溶胶对大气吸收太阳辐射的影响

云通过辐射过程对地气系统的能量平衡起着特别显著的调节作用 ,是影响天气、气候以及全球变化的重要因子。近年来 ,有云大气对太阳短波辐射的“异常吸收”又成为云—辐射研究中的一个争论热点。有云大气的短波吸收受到多种因素的影响 ,关于这方面的研究还不够充分。本文通过计算 ,从理论上探讨了若干因素的组合对大气吸收的综合影响。在计算中 ,同时考虑了不同太阳辐射波段、不同太阳入射天顶角、不同云顶高度以及不同下垫面的影响 ,并考虑了包含大气分子、气溶胶和云滴的吸收与散射 ,以及在近红外波段大气自身的热辐射等过程 ,阐明了云与气溶胶在不同波段对大气吸收太阳辐射的影响。     

地磁场对1999年9月空间天气大事件的响应

1999年9月22－25日发生一个大磁暴（Dst=-164nT).磁暴主相开始的头1小时伴随有丰富的Pc型地磁脉动，包括Pc2,Pc3,Pc4等。在行星际磁场Bz由北向转向南向后，磁暴主相开始，南向分量达到最大值后大约2小时，地磁H分量达到最小值，恢复相开始，并且，这次磁暴与太阳风各参数以及星际电场也存在一定的对应关系。     

地磁太阳黑子周变化起源的讨论

为了避开60年代末和70年代末Jerk(H)、Jerk(Z)的影响,分析了1979～1998年西欧4个台和1979～1999年亚洲东部6个台的H、Z资料,结果表明各台间H(或X)分量的太阳黑子周变化一致性较好.但Z分量的太阳黑子周变化显示出非常特别的现象,Z变化的相位随台站经度变化而变化,东亚地区的Z变化几乎与西欧地区的变化反向.因此,东亚地区的Z变化与H变化的关系不符合P01模式的假设,外源场之说似乎不能解释.     

Local time variation of geomagnetic transfer functions

The local time (LT) variation of the geomagnetic transfer function at the 32-min period was examined for observatories distributed worldwide. Two distinct variation types (types 1 and 2) were found in the real part of A. Type 1 is conspicuous at lower latitudes and its seasonal variation is small, whereas type 2 is found at higher latitudes and has its maximum in summer. These two types of LT variation are seen globally and are conspicuous when solar activity is high. The amplitudes of both types of variation vary from 0.018 to 0.078, and are independent of the mean values at each observatory. These values are relatively small, but the amplitude of Chambon la Foret is larger than the mean value, which shows that Au changes its sign in local time. The amplitudes of type 1 and 2 variations decrease and increase with geomagnetic latitude, respectively. These features suggest that they are generated by some global external fields. The most probable cause is the Sq field, although the Dp field may contribute to type 1 variation. On the other hand, for the islands of the Pacific Ocean at low latitudes, such as Honolulu and Chichijima, the type 1 variation appears not in the real but in the imaginary part of A, which suggests that currents induced in the ocean also contribute to the local time variation.     

The influencing factors and mechanisms of the electromagnetic radiation during rock fracture

ＴｈｅｉｎｆｌｕｅｎｃｉｎｇｆａｃｔｏｒｓａｎｄｍｅｃｈａｎｉｓｍｓｏｆｔｈｅｅｌｅｃｔｒｏｍａｇｎｅｔｉｃｒａｄｉａｔｉｏｎｄｕｒｉｎｇｒｏｃｋｆｒａｃｔｕｒｅＹＵ－ＺＨＯＮＬＩＵ１）（刘煜洲）ＹＩＮＬＩＵ１）（刘因）ＹＩＮ－ＳＨＥＮＧＷＡＮＧ２...     

CLIMATIC CHARACTERISTICS OF ATMOSPHERIC NET RADIATION OVER CHINA*

In terms of ERBE and ISCCP data.and measured/calculated surface net radiation,computation is performed of the climatic characteristics of ANR(atmospheric net radiation) across China alongside with the discussion and relations to other two kinds of radiation and contributing factors.Evidence suggests a high linear correlation of ANR with atmosphere-absorbed shortwave radiation.whereby can be established a general expression for ANR,which decreases more sharply as a function of altitude and increases slightly with latitude in summer,and changes uniformly in winter.Eventually,a comparison is made of the findings presented in this paper and literatures regarding the ANR pattern and magnitudes,indicating their great difference.     

THE CALCULATION AND ANALYSIS OF SLOPE NET RADIATION IN CHINA*

By using the climatological calculating method for each component of slope surface net radiation proposed by the authors,calculations and analyses are done of the distribution features of slope net radiation in China with emphasis on the discussion of variations of slope net radiation in typical stations and sites with slope direction,slope,latitude and season.The distribution features of net radiation on the north and south slopes are,for the first time,mapped and discussed,revealing the great difference on the national basis,and thus acquiringa new interesting result that the negative-value area of winter net radiation on the north slope(20°)can reach Yunnan and Guizhou Provinces and middle and upper reaches of the Changjiang River.     

Variations in the strength of recurrent geomagnetic activity in solar cycles 11 to 21

From maximum entropy spectral analysis (MESA) of short lengths ofAa indices of geomagnetic activity, the characteristics of the strength of the 27-day and 13.5-day signals for each of the solar cycles 11 to 21 are highlighted. It is shown that the 13.5-day signal is a near permanent feature in geomagnetic activity. The Hale-cycle (22 yr) effect could be seen in the average magnitude of the 27-day signal with greater strengths in the even cycles. No clear annual variation in the strength is noticed, contrary to some earlier known results.     

Hydrodynamic effects in a reservoir with semicircular cross-section and absorptive bottom

A three-dimensional dam-reservoir system under seismic load is analysed. The dam is assumed to be rigid. The reservoir is an infinite channel with semi-circular cross-section. The exact analytical solution, based on the assumption of potential fluid motion is presented, as well as numerical results for selected parameters.The most significant parameters are: the direction and frequency content of the seismic input; the radiation damping at the reservoir bottom; and the compressibility of the fluid. The response of the system depends strongly on the direction of the input ground motion. This is shown by the transfer functions as well as by the pressure time histories due to two earthquakes with different frequency content. The energy absorption at the reservoir bottom is important. A simple plane-wave model shows, that even for a rock foundation, the amount of transmitted energy can reach up to 80%. For comparison the case without bottom absorption is also shown. Compressbility has to be included to capture the resonance effects. The exact analytical solution is also used to verify numerical results obtained by a new method that combines a finite element model with a rigorous radiation boundary for the infinite channel in the time domain.