1950～1990年中国地磁剩余场冠谐分析

根据中国1950、1960、1970、1980年和1990年地磁三分量绝对测量资料，使用球冠谐和分析方法，分别计算1950～1990年各个年代中国地磁剩余场冠谐模型. 球冠极点位于36°N和104°E，球冠半角为30°，冠谐模型的截断阶数为8. 地磁剩余场冠谐模型的均方偏差分别为：对于X分量，1950年为93.1 nT，1960年为128.9 nT，1970年为107.2 nT，1980年为107.6 nT，1990年为95.2 nT；对于Y分量，1950～1990年依次为74.8 nT，98.1 nT，89.2 nT，89.9 nT和84.0 nT；对于Z分量，分别为122.2 nT(1950年)，135.0 nT(1960年)，137.7 nT(1970年)，110.1 nT(1980年)和107.5 nT(1990年). 根据中国地磁剩余场冠谐模型和全球地磁场DGRF模型，得到中国地磁场的冠谐模型，并对冠谐模型的边界效应进行了分析和讨论.     

致密砂岩的形成机制及其地质意义——以塔里木盆地英南2井为例

砂质岩的孔隙和喉道被网格状粘土矿物和次生加大矿物充填成微细孔喉状结构时,形成具有较高毛细管压力的致密砂岩。它与地层水发生水锁效应,可大大降低渗透率,成为致密砂岩盖层。当含水饱和度在50%以下时,束缚水饱和度比较低,致密砂岩储层可以产气;当含水饱和度在50%～90%区间时,具有较高的束缚水饱和度,相对渗透率非常低,它既不能产气也不能产水,反映为渗透率瓶颈区(具有盖层性质);当含水饱和度大于90%以上时,致密砂岩储层仅微量产水。塔里木盆地英南2井侏罗系气藏盖层由致密砂岩构成,不含水时的气体渗透率在(0.027～0.081)×10-3μm2,不能构成封堵;当含水饱和度达到60%以上时,相对渗透率几乎为零,构成有效盖层。     

空心微珠轻质保温帽的研制

论述以厚壁空心微珠为基质,研制轻质保温帽。重点阐述原材料的物理化学性质,配料组成的确定,工艺流程。经工业试验,试制出轻质、高强的绝热材料,经济、社会效益显著。为粉煤炭的产品型利用提供新途径。     

动态金幔柱模式──兼论金星上小型冠状构造的浅起源

热和组分密度异常共同驱动的动态金幔柱解析模式给出金幔柱在金幔中上升的历史．当金幔柱到达岩石层底时其头部的特征量是5个独立变量的函数：（1）金幔柱起源的深度;（2）金幔粘性系数;（3）源温度异常值;（4）源组分与热密度异常之比;（5）金幔柱的浮力通量．基于新的Mapellan数据,金星表面上有360多个冠状和类冠状构造已被发现,其中65％直径小于300km．这类小型冠状构造被认为是由具有下述特征的较小的金幔柱所形成：（1）最大直径小于300km;（2）当其头部到达岩石层底时,过剩温度足以产生部分熔融层,应高于150K;（3）被冠状构造下面的金幔柱带上来的总浮力有能力支撑冠状构造隆起的总质量．用这3个条件分析数值结果并约束金幔柱的源参数,根据本文的数值实验结果,金星上的小型冠状构造可能是起源于上金幔小于1000km深度的动态金幔柱形成的．     

Using large radio telescopes at decametre wavelengths

With the aim of evaluating the actual possibilities of doing, from the ground, sensitive radio astronomy at decametre wavelengths (particularly below ), an extensive program of radio observations was carried out, in 1999–2002, by using digital spectral and waveform analysers (DSP) of new generation, connected to several of the largest, decametre radio telescopes in the world (i.e., the UTR-2 and URANs arrays in Ukraine, and the Nançay Decametre Array in France).

We report and briefly discuss some new findings, dealing with decametre radiation from Jupiter and the Solar Corona: namely the discovery of new kinds of hyper fine structures in spectrograms of the active Sun, and a new characterisation of Jupiter's “millisecond” radiation, whose waveform samples, with time resolution down to 40 ns, and correlated measurements, by using far distant antennas (3000 km), have been obtained. In addition, scattering effects, caused by the terrestrial ionosphere and the interplanetary medium, could be disentangled through high time resolution and wide-band analyses of solar, planetary and strong galactic radio sources. Consequences for decametre wavelength imaging at high spatial resolution (VLBI) are outlined. Furthermore, in spite of the very unfavourable electromagnetic environment in this frequency range, a substantial increase in the quality of the observations was shown to be provided by using new generation spectrometers, based on sophisticated digital techniques. Indeed, the available, high dynamic range of such devices greatly decreases the effects of artificial and natural radio interference. We give several examples of successful signal detection in the case of much weaker radio sources than Solar System ones, down to the intensity level.

In summary, we conclude that searching for sensitivity improvement at the decametre wavelength is scientifically quite justified, and is now technically feasible, in particular by building giant, phased antenna arrays of much larger collecting area (as in the LOFAR project). In this task, one must be careful of some specifics of this wavelength range—somewhat unusual in “classical” radio astronomy—i.e., very high level and density of radio interference (telecommunications) and the variable terrestrial ionosphere.     

Woody vegetation and land cover changes in the Sahel of Mali (1967–2011)

In the past 50 years, the Sahel has experienced significant tree- and land cover changes accelerated by human expansion and prolonged droughts during the 1970s and 1980s. This study uses remote sensing techniques, supplemented by ground-truth data to compare pre-drought woody vegetation and land cover with the situation in 2011. High resolution panchromatic Corona imagery of 1967 and multi-spectral RapidEye imagery of 2011 form the basis of this regional scaled study, which is focused on the Dogon Plateau and the Seno Plain in the Sahel zone of Mali. Object-based feature extraction and classifications are used to analyze the datasets and map land cover and woody vegetation changes over 44 years. Interviews add information about changes in species compositions. Results show a significant increase of cultivated land, a reduction of dense natural vegetation as well as an increase of trees on farmer's fields. Mean woody cover decreased in the plains (−4%) but is stable on the plateau (+1%) although stark spatial discrepancies exist. Species decline and encroachment of degraded land are observed. However, the direction of change is not always negative and a variety of spatial variations are shown. Although the impact of climate is obvious, we demonstrate that anthropogenic activities have been the main drivers of change.     

Low-frequency solar radiophysics with LOFAR and FASR

Low-frequency radio observations offer unique diagnostics of the solar corona and solar wind. After a prolongued hiatus, there is renewed interest in this important frequency regime. Two new ground-based instruments will provide critical new low-frequency observations: the low-frequency array (LOFAR) and the frequency agile solar radiotelescope (FASR). This brief topical review summarizes low-frequency radio phenomena that will be accessible to detailed study by LOFAR and FASR in the coming decade. Energy release, drivers of space weather, and studies of the solar wind are emphasized. Both instruments are expected to play important roles in both basic research problems and national and international space weather capabilities. While FASR is a solar-dedicated instrument, LOFAR is not. Solar observing requirements for LOFAR are briefly discussed.