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磁变仪保温与防潮 总被引：1，自引：0，他引：1
朱贤长 《地震地磁观测与研究》1991,12(4):63-65,62
我国各地磁台站的相对记录仪器,目前仍然使用磁变仪。而温度和潮湿是影响仪器正常工作的两大因素。怎样尽量减少这些因素对仪器产生的影响,提高观测资料的内在质量?本人通过十多年台站工作实践,有一些想法在此和大家一起讨论,希望能够起抛砖引玉的作用。 相似文献
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近年，我国建立了大批的数字化地震台站，数字地震观测正逐渐取代模拟观测。而其地震计因采用电子反馈技术及其较宽的频带等，容易受到潮湿、气流扰动、温度变化等因素的影响，使地震记录产生无规则的漂移，尤其是仿真中长周期后更明显。为解决这些问题，本文介绍一种用于FBS-3A型地震计的保温防潮防护罩的设计制作原理，鹤岗地震台实际使用后效果显著。 相似文献
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对多种墙体保温材料、多种不同构造组成的保温系统进行了多项室内外防火性能试验。两面墙体外保温系统分别为胶粉聚苯颗粒贴砌聚苯板和聚苯板薄抹灰系统。以保温系统的外饰面(涂料饰面和面砖饰面)为例,阐述了保温系统的防火试验方法。通过对试验测试数据的处理,得出了保温系统温度和温度场的变化规律。揭示了保温系统在火灾试验的过程中,两种墙体的保温系统在火灾作用下的燃烧速度和火势蔓延的范围。将温度及温度场变化规律和燃烧后保温系统的破损情况进行比较,得出本构造材料可提高保温系统的防火性能的结论。 相似文献
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利用新型保温材料--聚氨酯硬质泡沫塑料,对地磁相对记录室实施喷吐保温改造,在很大程度上降低了磁房温度的日差、年差幅度,改善了观测环境,为观测仪器能在相对较小的温差范围内工作,创造了良好条件.聚氨酯硬质泡沫塑料作为一种新型的保温材料,对磁房实施保温是很好的一种选择,在今后的磁房建设或改造中,值得推广应用. 相似文献
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正"从前,我们的住房建筑仅仅要求满足‘住’的需求。今天,我们的住房不光要满足‘住’更要满足绿色、节能的需求。"在不久前举行的第十二届国际绿色建筑与建筑节能大会暨新技术与产品博览会上,国务院参事、住建部原副部长仇保兴表示,我国的建筑不能一味追求奢侈、浪费和讲排场,在全球应对气候变化的挑战面前,绿色建筑的发展将扮演一个重要的角色。 相似文献
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地磁观测条件的特殊性决定了仪器观测室建设具有难度，本文介绍了大连地震台按照《地震及前兆数字指导规范（试行）》要求建设磁通门仪器室的过程及结果。 相似文献
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陈万山 《地震工程与工程振动》2013,33(1):67-72
为研究带缝空心保温钢筋混凝土剪力墙的耗能性能,设计并制作了3组钢筋混凝土空心保温剪力墙。通过水平低周反复荷载试验,研究了该剪力墙的破坏机理、滞回特性、延性与耗能性能等力学性能,分析了竖缝形式、连接键等对空心保温剪力墙耗能性能的影响。研究表明:设置竖缝和连接键可以改变剪力墙的受力模式,使剪力墙在刚度和承载力下降较小的情况下,延性和抗震性能得到较大提高。由于耗能机理的转变,连接键、竖缝内的钢筋和橡胶带参与耗能,较大程度地提高剪力墙的耗能性能。 相似文献
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本文詳細地介紹了武汉采用的交点相关法和十点相关法的理論基础和具体計算方法,并与Philtips和spcncer的相关法（PS法）及Yerg的六点相关法进行了比較。正如理論上所預期到的,武汉的实驗表明:交点法提供的参量最多,也最精确可靠,但計算量与PS法的差不多;十点法提供的参量与交点法的一样多,精确性不此PS法的低,然而計算量比PS法的少得多,与六点法的差不多。文中还討論了利用时移图上曲直线,以进一步提高十点法的精确性,以及在相关分析中采用結构函数和后效函数,以进一步簡化計算的可能性。本文还初步討論了各种相关分析法的誤差間題;并提出了相关函数值在时空上的預报方法,以及根据相关函数的預报值与实測值的对此等,判别在記录分析中有无反常現象,和甄別所求出的参量值是否可疑的方法。最后还特別指出了电离层混乱运动变化速度出現虛数值的可能性,并介紹了消除这种虛数值的方法。 相似文献
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滇池东北岸生态修复区的环境效应--Ⅰ.抑藻效应 总被引：7，自引：0，他引：7
研究了滇池东北沿岸带生态修复区抑制蓝藻水华的功能,对比监测了修复区内外水体中chl.a浓度,通过原位围隔试验研究了修复区内聚集藻类的降解过程,测定了水生植被的遮光率及其对藻类光合作用的影响。结果显示,修复区具有捕获富集和分解消除漂浮性蓝藻的作用,同时能通过水生植物的遮荫作用抑制藻类光合作用。在蓝藻水华暴发期(7-10月)修复区内蓝藻大量聚集,chl.a最高浓度达到修复区外的29倍;聚集在修复区内的藻类在微生物作用下迅速降解,chl.a降解过程符合一级反应动力学方程,反应系数为k=0.2173(时间单位为天);修复区内挺水植被的遮光率可以达到90％以上,能降低植被区内水体中藻类光合作用强度60％左右。 相似文献
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Keisuke Ito 《Earth and Planetary Science Letters》1980,51(2):451-456
The chaotic dynamics of the Rikitake two-disc dynamo system is studied for a wide range of parameters and results are compared with the sequence of geomagnetic polarity reversals. The chaos of the Rikitake system belongs to the Lorenz type, which is characterized by irregular travelling of an orbit between two unstable fixed points. Travelling corresponds to the polarity reversal. The frequency of the polarity reversals depends strongly on the parameter μ representing the resistive dissipation in the core. In the center of the chaotic regime, there is a parameter region in which reversals seldom occur and the dynamics is less disordered. The Markov entropy of the Lorenz map for the system has a sharp minimum in this parameter region named as the minimum entropy regime (M.E.R.). The average frequency of reversals in the M.E.R. is less than 0.1 per cycle of oscillation, but is not uniform even seen through a 10-m.y.-long window. The non-uniformity as well as the low rate of reversals in the M.E.R. markedly resemble the behavior of geomagnetic reversals over the past 153 m.y. It is suggested that the Earth selected the minimum entropy regime on the principle of the minimum entropy production, as is known to be the case for other dissipative dynamical systems. 相似文献
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A comparative numerical investigation of transient temperature profile and pore-air velocities in horizontal rock block embankments are conducted using the “gravels model”, in which the embankment is composed of stones and air, and the “porous media model” respectively. As the velocities from the “gravels model” directly reflect the true flow of air and winter-time convection, in this paper it can be concluded that computational results from the “gravels model” are superior to the “porous media model”. In addition, the “gravels model” has the advantages of reflecting the effect of the dimensions and collocation of gravels upon the temperature fields. Therefore, the computation of the gravels embankment is mainly based on the gravels model. Simulation results show that in summer, a clockwise circulation of the pore-air extends throughout most of the embankment. However its motion is very weak that results in relatively straight horizontal isotherm lines. And heat transfer is mainly maintained through conduction. But in winter, the pore-air velocities are higher and multiple vortexes are formed in the embankment. Natural convection then becomes the dominant influence on the isotherm shapes within the embankment. The isotherms are complex and alternative upward and downward flowing plumes exist. The winter-time convection can further reduce the temperature of the foundation soil beneath the gravel embankment. In addition, the effects of the gravel dimensions within the embankment have been analyzed and compared in the gravels model. It shows that in winter, large stones, e.g. 200 mm, lead to stronger vortexes than those of small stones, say 60 mm. Consequently, the zone of low-temperature beneath the large-stone embankment extends deeper into the ground. 相似文献
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Apatite Fission Track (AFT) data from the Songliao Basin indicates that the late stage tectonic movements in the Songliao Basin have zoning in space and episodes in time. The late stage tectonic movements started from the east part of the basin and migrated westward. AFT ages in the east part of the basin are older than those in the west part of the basin, suggesting that the uplift occurred earlier in the east than in the west. The denudation thickness in the east part of the basin is significantly greater than that in the centre and west. The thermal history evolved two episodes of rapid cooling and subsequent slow cooling processes. Age-depth relationship derived from the AFT data indicates a four-episode denudation history. Further Monte Carlo random simulation of the AFT data reveals the four changing points of the thermal evolution at 65 Ma, 43.5 Ma, 28 Ma and 15 Ma, respectively. The uplifting and denudation rates from different episodes of evolution are proportional to the plate convergence rate. Based on the above analyses and the regional geologic background, it is concluded that the late stage thermal events in the Songliao Basin are the far field response to the subduction of the Pacific Plate under the Eurasian Plate. The first episode of the rapid cooling probably started at the end of the Nenjiang Formation, climaxed at the end of the Cretaceous and ceased at the Late Eocene. The subsequent slow cooling lasts another 15 Ma. The first episode of the evolution is the far field response to the major episode of the Yanshan Movement and subsequent series of the tectonic reorganization, especially the directional change of the Pacific Movement and also the subduction of the Indian Plate underneath the Eurasian Plate. While the second episode of the evolution is the far field response to the extension and closure of the Sea of Japan. Extension led to the migration and converging of the mantle heat flow to the Sea of Japan and resulted in the rapid cooling of the Songliao Basin. 相似文献
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Dr. S. Kornis 《国际泥沙研究》1989,(1)
1. INTROOrCTIOXThe upper Tisza in Hungary is a sand bed alluvial river. presenting several river training problems. In order to solve these problems first the laws of free river--bed evolution must be clarified thenthe effects of existing river training s… 相似文献
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大地震发生后,估计后续地震发展趋势是人们关心的问题.目前,学术界经常利用大地震造成的库仑应力变化研讨大震对后续地震的影响,但库仑应力的计算和应用中尚有一些问题被忽视而有待探讨.本文修正了传统的库仑应力计算中沿地震破裂面滑动方向计算剪应力变化的近似方法,考虑震后主应力方向可能改变对剪应力变化量计算的影响,对改进方法和传统方法获得的结果进行了对比分析.本文基于龙门山地区背景应力场测量资料,根据不同研究者反演的地震破裂模型,计算了汶川地震造成的静态库仑应力变化,考察了不同地震破裂模型下库仑应力分布差异.在断层面附近,使用改进方法与传统方法计算的库仑应力分布差异相当大;利用多个地震破裂模型计算大地震库仑应力判断大震后余震发展趋势时,要注意破裂模型不确定性对危险性估计的影响. 相似文献
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Studies of marine magnetic anomaly data from the Shikoku basin reveal magnetic lineations which strike northwest almost parallel to the trend of the Palau-Kyushu ridge. The lineation pattern is best developed in the western part of the basin and we can confidently identify a sequence of anomalies 7 through 5E between the base of the Palau-Kyushu ridge and the center of the basin. In the eastern part of the basin the basement morphology is rough and complex and magnetic anomalies can not be identified unequivocally. We infer that the Palau-Kyushu ridge and the Izu-Bonin island arc began separating about 27 m.y. B.P. An interval of rapid separation (4.2 cm/yr) occurred between 26 and 22.5 m.y. B.P. which approximately coincides with a period of intense volcanic activity in Japan. The observed magnetic lineation pattern and basement morphology can be best explained if the Shikoku basin formed at a two-limb spreading system during the Late Oligocene to Middle Miocene. Subsequently the eastern half of the basin was disrupted by fractures as the Iwo-Jima ridge collided with the Japanese islands. The accretionary process which formed the crust of the Shikoku marginal basin appears similar to that operating at mid-ocean ridges of the world. 相似文献
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大地震发生之后通常会诱发一系列的余震序列,对比1976年MS7.8唐山大地震和2001年MS8.1昆仑山大地震周边区域的地震事件可以看出,唐山大地震余震活动时间要明显长于昆仑山大地震余震活动时间.余震序列往往与震后形变密切相关,而影响震后形变的因素不仅与地震发震断层和震级有关,同时与岩石圈的结构有关.考虑到唐山大地震的发震区华北地块和昆仑山大地震的发震区青藏高原有着较大的岩石圈结构差异,本文采用PSGRN/PSCMP软件计算了岩石圈分层模型的大地震同震和震后形变,分析了地壳弹性模量、弹性厚度以及黏滞性系数对同震和震后形变的影响,进而讨论了影响唐山地震和昆仑山地震余震序列差异的原因.计算结果显示,震后形变会在黏弹性效应的作用下逐渐调整,震后形变的持续时间与地壳弹性模量、地壳弹性厚度和下地壳黏滞性系数有关.上地壳和下地壳弹性模量越大,震后形变达到稳定值的时间越短,弹性模量对震后形变稳定值影响很小.地壳弹性厚度越大,震后形变达到稳定值的时间越短,当断层面底端深度小于地壳弹性厚度时,地壳弹性厚度的增加会引起震后形变稳定值的减小;下地壳厚度对震后形变达到稳定值的时间和稳定值基本无影响.下地壳黏滞性系数越大,震后形变达到稳定值的时间越长,反之亦然.结合唐山地震区的华北地块和昆仑山地震的青藏高原深部结构发现,两者之间的上地壳弹性模型差别不大,唐山地震区地壳弹性厚度略大于昆仑山地震区,但昆仑山地震区下地壳黏滞性系数明显低于唐山地震区.这些因素均决定了昆仑山地震的震后形变持续时间短（余震时间序列短）而唐山地震的震后形变持续时间长（余震时间序列长）.由此可见,岩石圈结构差异可能是导致唐山地震和昆仑山地震余震序列差异的主要因素之一. 相似文献