Evidence of shallow fault zone strengthening after the 1992 M7.5 landers, california, earthquake

Repeated seismic surveys of the Landers, California, fault zone that ruptured in the magnitude (M) 7.5 earthquake of 1992 reveal an increase in seismic velocity with time. P, S, and fault zone trapped waves were excited by near-surface explosions in two locations in 1994 and 1996, and were recorded on two linear, three-component seismic arrays deployed across the Johnson Valley fault trace. The travel times of P and S waves for identical shot-receiver pairs decreased by 0.5 to 1.5 percent from 1994 to 1996, with the larger changes at stations located within the fault zone. These observations indicate that the shallow Johnson Valley fault is strengthening after the main shock, most likely because of closure of cracks that were opened by the 1992 earthquake. The increase in velocity is consistent with the prevalence of dry over wet cracks and with a reduction in the apparent crack density near the fault zone by approximately 1.0 percent from 1994 to 1996.     

Variation of interplate fault zone properties with depth in the japan subduction zone

The depth dependence of physical properties along the Japan subduction zone interface was explored using teleseismic recordings of earthquake signals. Broadband body waves were inverted to determine the duration of rupture and source depth for 40 interplate thrust earthquakes located offshore of Honshu between 1989 and 1995. After scaling for differences in seismic moment, there is a systematic decrease in rupture duration with increasing depth along the subducting plate interface. This indicates increases in rupture velocity or stress drop with depth, likely related to variation in rigidity of sediments on the megathrust.     

Role of fault bends in the initiation and termination of earthquake rupture

Rupture in individual earthquakes apparently is limited to regions between bends in faults. This is illustrated for eight events that have occurred since 1966. A model based on geometric concepts describes why this is so and clarifies earlier ideas of "asperities" and "barriers" used to explain earthquake initiation and termination processes. Because of their importance in the rupture process, bend zones should be monitored for precursory effects.     

Subducted seamount imaged in the rupture zone of the 1946 nankaido earthquake

The Nankai Trough is a vigorous subduction zone where large earthquakes have been recorded since the seventh century, with a recurrence time of 100 to 200 years. The 1946 Nankaido earthquake was unusual, with a rupture zone estimated from long-period geodetic data that was more than twice as large as that derived from shorter period seismic data. In the center of this earthquake rupture zone, we used densely deployed ocean bottom seismographs to detect a subducted seamount 13 kilometers thick by 50 kilometers wide at a depth of 10 kilometers. We propose that this seamount might work as a barrier inhibiting brittle seismogenic rupture.     

小型变压器生产过程中的故障分析

变压器几乎在所有的电子产品中都要用到,它原理简单但根据不同的用途,变压器的绕制工艺也会有所不同的要求。变压器的功能主要有:电压变换;阻抗变换;隔离;稳压(磁饱和变压器)等,变压器常用的铁芯形状一般有E型和C型铁芯[1]。本文主要介绍小型变压器的工作原理、生产过程中常见故障及解决方法,重点分析在生产过程中出现最多且较难解决的耐电压不良,使其在生产过程中避免不良现象发生,减少材料的浪费,提高成品的合格率,提高企业生产的效益。     

Isotropic events observed with a borehole array in the Chelungpu fault zone, Taiwan

Shear failure is the dominant mode of earthquake-causing rock failure along faults. High fluid pressure can also potentially induce rock failure by opening cavities and cracks, but an active example of this process has not been directly observed in a fault zone. Using borehole array data collected along the low-stress Chelungpu fault zone, Taiwan, we observed several small seismic events (I-type events) in a fluid-rich permeable zone directly below the impermeable slip zone of the 1999 moment magnitude 7.6 Chi-Chi earthquake. Modeling of the events suggests an isotropic, nonshear source mechanism likely associated with natural hydraulic fractures. These seismic events may be associated with the formation of veins and other fluid features often observed in rocks surrounding fault zones and may be similar to artificially induced hydraulic fracturing.     

海峡西岸经济区投资结构与产业结构优化探析——以福建省为例

海峡西岸经济区建设的顺利进行,是与其产业结构和投资结构是否协调发展密切相关的,而福建省作为海峡西岸经济区的主体,其产业结构和投资结构是否合理,直接影响了福建省经济的又好又快发展,进而影响海峡西岸经济区建设的整体质量和进程。本文通过对福建省产业结构和投资结构的现状进行比较系统的探析,指出其存在的问题,并对福建省产业结构和投资结构的优化提出几点建议。     

Fine structure of muscle cells of the human testicular capsule: basis of testicular contractions

Electron micrographs of human testicular capsule reveal large numbers of branching smooth muscle cells coursing through collagenous tissue of the tunica albuginea. These cells have subcellular morphology characteristic of smooth muscle cells, and they associate with one another through areas of close contact. These are the contractile cells responsible for spontaneous contractions of the human testicular capsule-contractions that may be important in transporting nonmotile sperm out of the testis.     

Fine thermal structure of a coronal active region

The determination of the fine thermal structure of the solar corona is fundamental to constraining the coronal heating mechanisms. The Hinode X-ray Telescope collected images of the solar corona in different passbands, thus providing temperature diagnostics through energy ratios. By combining different filters to optimize the signal-to-noise ratio, we observed a coronal active region in five filters, revealing a highly thermally structured corona: very fine structures in the core of the region and on a larger scale further away. We observed continuous thermal distribution along the coronal loops, as well as entangled structures, and variations of thermal structuring along the line of sight.     

加工番茄离区发育过程及有无离区相关生理特性分析

以有离层和无离层品种的加工番茄为试材,采用石蜡切片技术和番红-固绿染色法对花梗进行解剖学研究,并对完全形成离层的时期(花完全开放时期)进行生理生化方面的研究.结果表明,离层是在花芽分化过程中逐步产生的,并伴随着花梗的生长而生长.在花完全开放时期,离层品种中细胞壁降解酶的活性显著高于无离层品种,而可溶性蛋白含量与酶活性呈负相关性.研究为进一步探讨离区发育机制奠定理论基础,也对生产中防止落花落果具有重要指导意义.     

基于CT处理技术的岩石细观破裂过程的分形分析

在单轴压缩条件下,利用CT技术实时观测岩石试样内部微裂纹的萌生、扩展直至贯通的细观破坏过程,通过数字处理技术对得到的CT图像进行阈值分割并利用计盒维数法得到图像裂纹的分形维数,分析外部荷载、裂纹扩展和分形维数之间的关系。结果表明:在单轴压缩条件下,分形维数可以作为岩石材料细观破损程度的定量参数。     

Laboratory earthquakes: the sub-Rayleigh-to-supershear rupture transition

We report on the experimental observation of spontaneously nucleated supershear rupture and on the visualization of sub-Rayleigh-to-supershear rupture transitions in frictionally held interfaces. The laboratory experiments mimic natural earthquakes. The results suggest that under certain conditions supershear rupture propagation can be facilitated during large earthquake events.     

RS-Net: robust segmentation of green overlapped apples

Fruit detection and segmentation will be essential for future agronomic management, with applications in yield estimation, growth monitoring, intelligent picking, disease detection and etc. In order to more accurately and efficiently realize the recognition and segmentation of apples in natural orchards, a robust segmentation net framework specially developed for fruit production is proposed. This model was improved for the more challenging problem which segments the overlapped apples from the monochromatic background regardless of various corruptions. The method extends Mask R-CNN by embedding an attention mechanism for focusing more on the informative pixels but also suppressing the noise caused by adverse factors (occlusions, overlaps, etc.), which could be more suitable and robust for operating in complex natural environment. Specifically, the Gaussian non-local attention mechanism is transplanted into Mask R-CNN for refining the semantic features generated continuously by residual network and feature pyramid network, then the model forward processing based on the balanced feature levels and finally segments the regions where the apples are located. Experimental results verify the hypothesis of current work and show that the proposed method outperforms other start-of-the-art detection and segmentation models, the AP box and AP mask metric values have reached 85.6% and 86.2% in a reasonable run time, respectively, which can meet the precision and robustness of vision system in agronomic management.

     

台湾工业化进程中农业结构的升级及其动因

农业结构的形成和演变 ,不仅取决于农业内部资源禀赋的状况 ,而且受到工业化发展水平的制约。随着工业化水平的提高 ,农业结构也因应实现了升级和换代。本文剖析了台湾工业化进程中农业结构升级的三个阶段 ,并揭示其内在动因     

农业结构效率决定性因素层次分析

利用层次分析法对影响农业结构效率的宏观和微观2个方面的主要因素作了量化分析，并计算了各主要因素对农业结构效率的贡献率。结果表明，农业结构效率不高的主要原因来自于宏观层次，主要影响因素的影响程度依次为：农业政策，农业科技，比较优势，生产者素质和消费结构。     

Naphthaleneacetic Acid: localization in the abscission zone of the bean

When (14)C-naphthaleneacetic acid, labeled in the ring, was applied to the petiolar stuib of debladed bean (Phaseolus vulgaris L.) plants, it accumulated in or between cell walls of tissue immediately adjacent and distal to the abscission layer. There was no localization in the abscission layer per se. Similar distribution patterns were observed in the abscission zone after naphthaleneacetic acid applications, which either delayed (10(-3)M) or accelerated (10(-5)M) abscission.     

Molokai fracture zone: continuation west of the hawaiian ridge

The Molokai Fracture Zone is one of the principal east-west (striking) fracture zones between California and the mid-Pacific. On the basis of bathymetry alone, it has been assumed that the zone ended abruptly east of the Hawaiian Islands. Use of correlation techniques between bathymetric features and their magnetic anomalies in the vicinity of the islands now show that structural elements of the zone cross the islands and continue westward for at least 130 kilometers. Recent volcanism and deep rift zones of the islands parallel the zone, suggesting structural correlation between the strike of the zone and the origin of recent volcanism in the islands.