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1.
邢台矿区山字型构造的发现及其地质意义   总被引:1,自引:0,他引:1  
邢台山字型构造位于河北省邯邢煤田内,其前弧向ES突出,脊柱呈ES-WN走向。分别分析了山字型构造脊柱及其东、西翼反射弧构造形迹特征,对研究区找矿具有重要意义。  相似文献   
2.
Fisheries managers are increasingly promoting catch-and-release (C&R) to manage recreationally angled fish stocks. Despite this, there is a scarcity of information on the effects of C&R on estuarine-dependent species. Cape stumpnose Rhabdosargus holubi dominates the recreational fisheries catch and provides an important source of food for subsistence fishers in some temperate South African estuaries. The health and survival of R. holubi exposed to a C&R event was investigated by examining their physiological stress response (blood glucose and lactate), reflex impairment (reflex action mortality predictors [RAMP]) and short-term (12-hour) survival. Fish were captured and exposed to one of three air-exposure treatments: 0 s, 30 s or 90 s. Stress and health were measured either immediately (immediate) or one hour after (delayed) the C&R event. There was no significant difference in blood glucose between air-exposure treatments, but there was a significant difference between the mean immediate and delayed glucose levels within each treatment (F(2,143) = 81.8, p < 0.01). In contrast, blood lactate level was significantly higher in the 90-s treatment (p < 0.05). Immediate blood lactate levels were significantly lower than the delayed samples for each treatment (F = 4.29, p = 0.02; n = 169). Although all fish exhibited at least one reflex impairment, the RAMP score was significantly higher in the 90-s air-exposure treatment (H(2,86) = 9.73, p = 0.007). Also, RAMP scores were significantly lower in the delayed samples (p < 0.01). Although short-term mortality was relatively low (2.3%) for this species, it was highest in the 90-s treatment (7%). These results suggest that physiological stress is higher when R. holubi are exposed to longer periods of air exposure and that the physiological stress of fish subject to a C&R event is best measured after a delay.  相似文献   
3.
Optical buffers are critical for optical signal processing in future optical packet-switched networks. In this paper, a theoretical study as well as an experimental demonstration on a new optical buffer with large dynamical delay time is carried out based on cascaded double loop optical buffers (DLOBs). It is found that pulse distortion can be restrained by a negative optical control mode when the optical packet is in the loop. Noise analysis indicates that it is feasible to realise a large variable delay range by cascaded DLOBs. These conclusions are validated by the experiment system with 4-stage cascaded DLOBs. Both the theoretical simulations and the experimental results indicate that a large delay range of 1--9999 times the basic delay unit and a fine granularity of 25 ns can be achieved by the cascaded DLOBs. The performance of the cascaded DLOBs is suitable for the all optical networks.  相似文献   
4.
大庆油田嫩江组二段底部与嫩江组一段顶部成片套损严重,从前一直认为泥岩吸水膨胀、蠕变是导致成片套损的主要因素。成片套损位置研究发现,嫩江组二段底部与嫩江组一段顶部成片套损实际集中于嫩江组二段底部标志层内,而嫩江组二段底部标志层岩石矿物学特征综合研究结果表明,其不含遇水膨胀的蒙脱石,且粘土矿物含量也低于其上下相邻岩石,表明其遇水膨胀与蠕变较弱,岩石遇水膨胀与蠕变不会构成成片套损的主要原因。嫩江组二段底部标志层岩石岩心观察描述、镜下鉴定、矿物成分综合测试和岩石强度性质研究发现,嫩江组二段底部标志层泥岩为富含长英质的质地坚硬岩石,含粘土矿物较少,不含蒙脱石,岩石吸水能力差、膨胀与蠕变能力弱;标志层中存在多个化石富集带,化石沿岩石层理分布形成沿层理方向的区域性力学薄弱面;沿化石层层理的抗张强度与抗剪强度远低于其他层位和垂直于层理方向的强度性质。因此,一旦注入水进入嫩江组二段底部标志层,富含化石的岩石沿岩石层理优先发生破坏,并迅速扩展,形成成片套损现象。  相似文献   
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6.
王鹏云  朱勇  段长春  尚晓慧 《气象》1998,24(10):52-55
芒果运输中的环境温度对果实的呼吸代谢、蒸腾作用、酶活性、乙烯产生等生理生化过程起着主导作用,温度升高芒果成熟加快,易造成腐烂变质。为了改变运输过程中太阳辐射热造成的小环境增温,使用在塑料编织布上涂反射膜的方法,降低太阳辐射增温。经实测,反射膜能把85%的太阳辐射反射或散射掉,透过率低于10%,从而阻止了太阳辐射对车内的增温效应,避免了由于车内温度为对果实的伤害作用,为长途运输的降温了实用、简便的实  相似文献   
7.
张帆  贾方岩 《吉林地质》2013,(3):54-56,61
本文通过对野外实际水文电测深曲线的微分;即得到了反射系数K,通过对反射系数曲线的分析、推断;从而达到寻找地下水资源之目的。作者通过多年的野外工作实践,选出具有代表性的电测深曲线来论述了视电阻率微分曲线的实际应用效果。也为寻找地下水的方法应用得到了发挥。  相似文献   
8.
Abstract

This paper shows an experiment with tactile maps designed for visually impaired persons. Tests were carried out on a tactile map produced with 3D printing and including a new type of tactile symbols, volumetric symbols (3D). These symbols are localized faster than conventional flat relief symbols, with the same error rate, an improvement in the use of these tactile devices. Moreover, following tests, differences were found between types of participants with blind participants generally carrying out the proposed tasks better than the rest of users.  相似文献   
9.
根据地图表达地理属性的量表性质,将地图设色方案分为定性设色、顺序设色和双向设色等3种方式。基于这3种地图设色方式的特点,根据红-绿色盲的光谱特性,设计了一系列实验地图,通过颜色辨识的心理学实验,分析了红-绿色盲的视觉特征,初步揭示出一些针对红-绿色盲人群使用的地图设色原则,为制作红-绿色盲人群使用的地图提供了有效的参考。  相似文献   
10.
《The Journal of geography》2012,111(5):200-208
Abstract

Advances in classroom technology have lowered barriers for the visually impaired to study geography, yet few participate. Employing stereotype threat theory, we examined whether beliefs held by the visually impaired affect perceptions toward completing courses and majors in visually oriented disciplines. A test group received a low-level threat message that responses would be compared to sighted students, while a control group did not. Statistically significant differences were observed between the groups for the set of visual disciplines. Results indicated that threat messages did seem to influence participants’ perceptions; however, additional research is necessary.  相似文献   
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