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1.
On the bases of the studies of acoustic behavior and pattern recognition of budgerigar calls, the quantitative study on characteristic
parameters of acoustic behavior habits in budgerigars is further given in this paper. These results open up a new knowledge
for comprehensive analyses of abnormalities of acoustic behavior habits in budgerigars prior to earthquakes. Under indoor
lighting, the song calls in budgerigars are possessed of the beginning and ending singing time with the natural characteristics,
and of the rhythmic habit of daylight singings and night rests. In daily daylight and night calls, single calls, vari-toned
calls, mono-syllabic and multi-syllabic protest calls are respectively possessed of the occupation habit corresponding to
behavior activities, and have close acrophases and regular following properties corresponding to half-value phases, and the
acrophases delay half-value phases by about half an hour on an average. After reversing lighting, the acrophases of budgerigar
calls delay those of the normal lighting by about 12 hours on an average, and the following properties corresponding to half-value
phases are irregular.
This subject is supported by the Chinese Joint Seismological Science Foundation. 相似文献
2.
Ｑｕａｎｔｉｔａｔｉｖｅｓｔｕｄｙｏｎｃｈａｒａｃｔｅｒｉｓｔｉｃｐａｒａｍｅｔｅｒｓｏｆａｃｏｕｓｔｉｃｂｅｈａｖｉｏｒｈａｂｉｔｓｉｎｂｕｄｇｅｒｉｇａｒｓ（Ｍｅｌｏｐｓｉｔｔａｃｕｓｕｎｄｕｌａｆｕｓ）Ｊｉｎ－ＣｈａｎｇＪＩＡＮＧ（蒋锦昌）；Ｈ... 相似文献
3.
本文对自然条件下虎皮鹦鹉声行为观测资料，进行了微机分析，所得到的ＢＧ声行为特性很好地反映相应的自然习性，这就为地震生物观测站的ＢＧ声行为与地震关系观测资料的微机分析提供了基本方法，进而提高了动物习性异常在临震预报中的有效性，所得到的ＢＧ始鸣时和终鸣时，分别与观测站的日出和日没时呈正相关，变化速率都为０．２，即很好地反映ＢＧ声行为昼夜节律的季节变化习性。所得到的ＢＧ单次叫声，变音调叫声，单音节和多音 相似文献
4.
Jin-Chang Jiang Hai-Qiang Jin Yun-Fang Lin Hao Chen Xin-Yu Yang Xiao-Ping Zeng Xun Zhou 《地震学报(英文版)》1998,11(4):487-493
The effect of magnetic field-free space (MFFS) on the acoustic behavior of budgerigar (Melopsittacus undulafus) is obvious. The daily frequency of their cries in uniform MFFS (UMFFS) and non-uniform MFFS (NMFFS) decreases by 44.7±10.0%
as compared with that in the geomagnetic field (GMF) on the average. The occupation rate of protesting cries (R
op) in NMFFS decreases by 8.5%–20.3% as compared with that in GMF on the average and shows an adaptability variation. In 75%
of the observation days, the R
op in UMFFS increases by 16.2%–23.3% as compared with that in GMF. As for the effect of MFFS on the rhythmic habits of budgerigars,
only the ending time of crying is affected to certain extent, 67 minutes earlier than in GMF on the average.
This paper is supported by the Chinese Joint Seismological Science Foundation. 相似文献
5.
近年来,我国多数地震动物观察站(SAOS)监测虎皮鹦鹉(BG=budegerigar)的叫声频度与地震的关系,并取得了一些观测结果。但是,所用的声记录仪未能考虑BG叫声的声学特性,而不能分辨BG不同的叫声和进一步提取震兆性叫声模式(EPCP),并易受到环境噪声的干扰而产生误计数。 据此,分析了BG不同声行为叫声的声学特性。BG叫声大致上可分为单次叫声(SC)、变音调叫声(VTC)、单音节和多音节抗议叫声(MoSPC和MuSPC)。由此,进一步研制了它们的模式识别系统。该系统是以单片机为核心的微处理机,对BG叫声进行预处理、编码、分析、显示和打印输出。 观察结果表明,在高声场旅游飞机噪声(TAN)干扰下,该系统的BG叫声识别率(CRR)为66.7％,而对TAN没有误计数。在含10次不同声强的TAN干扰(432秒)的30分钟内,该系统记录了588次叫声(SC、VTC、MoSPC和SPC分别为377、22、20和169次),仅丢失65次叫声,其CRR平均为90％。但是,SAOS目前使用的声记录仪,这10次TAN干扰所产生的误计数可能约为BGU叫声的2.6—13倍。 由此可见,这种模式识别系统不仅可满足于BG不同叫声的识别,且具有良好的抗噪声功能。这就使之可为地震前BG声行为观测提供更有用的信息。不仅可给出BG叫声频度的昼夜节律变化与地震的关系,并可为揭示BG的EPCP提供一定的依据。 相似文献
6.
7.
The freshwater budget of a tidal flat area is evaluated from long-term hydrographic time series from an observation pole positioned in a tidal channel in the Hörnum Basin (Germany). For each tidal cycle, the freshwater budget is calculated from the total imported and exported water volumes and the corresponding mean densities. The variability of the budget on a tidal scale is characterised by a period of twice the tidal period, exhibiting a minimum when the tidal flats are dry around daylight hours during the foregoing low tide, and a maximum when low tide occurs at night; enhanced evaporation on the flats at daylight hours is identified as the driving process. On the average over one year, while winter observations are missing, the freshwater budget is negative for the years 2002–2005 and positive only for 2006. The interannual mean is negative and amounts to a freshwater loss of about 2 mm day−1, although the large-scale climate in this region is humid. The results demonstrate that the bulk parametrisations for the latent and sensible heat flux between the ocean and the atmosphere must not be applied for the tidelands. 相似文献
8.
Dr. J. Egedal 《Pure and Applied Geophysics》1948,11(1):1-7
Summary from earth-current observations made at Mogadiscio the lunar-diurnal variation has been derived for the northward component, and by means of a special method lunar variations during daylight hours and night hours have been determined separately. The results have been compared with corresponding results from other observatories.
Zusammenfassung Für die Nordkomponente des Erdstromes in Mogadiscio ist die mondentägige Variation abgeleitet worden, und ferner sind die lunaren Variationen dieser Komponente, für die Stunden des Tages und des Nachts getrennt, durch eine spezielle Methode hergeleitet worden. Die Resultate sind mit entsprechenden Resultaten anderer Observatorien verglichen worden.相似文献
9.
Vertical distribution of the dominant planktonic crustaceans in a mesotrophic reservoir, Xujiahe reservoir (central China) 总被引：1，自引：0，他引：1
The day and night vertical distributions of the dominant planktonic crustaceans in Xujiahe Reservoir were investigated on July 7, 1998. Sampling was carried out at Station D in the upstream region, Doupuohe, and Stations LI and LII in the downstream region, Lujiaodao. At Station D and Station LI, Leptodora kindti showed diel vertical migrations. In Daphnia galeata and Diaphanosoma dubia a limited reverse diel vertical migration was found at Station D, and large individuals tended to stay in lower layers during the day. Neutrodiaptomus incongruens seemed to avoid the water column of 0–6 m by day, but a detectable proportion of the population moved upwards at night. Mesocyclops thermocyclopoides showed a clearly defined diel vertical migration behavior at all three stations. The vertical distribution of Thermocyclops crassus was similar at different stations: in daylight hours it was found almost exclusively in the water column below 6 m and during the night a significant proportion of the population shifted upwards. 相似文献
10.
L. V. Egorova 《Geomagnetism and Aeronomy》2012,52(6):761-767
A joint analysis of variations in the ionospheric parameters at three vertical-incidence stations (Heiss Island, Dixon Island, and Sodankyla) and the solar wind plasma characteristics (i.e., the PC magnetic index characterizing the IMF geoeffective part) indicated that the PC index can be used as a predictor in order to diagnose the electron density level in the polar ionosphere. An increase in the PC level corresponds to positive and negative gradients in variations in the F region??s critical frequencies. As PC becomes larger than 1.5, the electron density increases at night in winter and, on the contrary, decreases during the day in summer and during daylight hours in winter. A delay in the ionospheric F region??s response to PC variations depends on the station latitude: this delay is no more than 1 and 2 h at the Heiss Island and Dixon Island stations and can be more than 6 h in summer and 0?C1 h in winter at Sodankyla. An increase in the PC amplitude as a rule corresponds to an anomalous increase in foEs relative to the median values at these stations with a delay of 1 h. 相似文献
11.
Stability analysis of MDOF real‐time dynamic hybrid testing systems using the discrete‐time root locus technique 
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下载免费PDF全文 The time delay resulting from the servo hydraulic systems can potentially destabilize the real‐time dynamic hybrid testing (RTDHT) systems. In this paper, the discrete‐time root locus technique is adopted to investigate the delay‐dependent stability performance of MDOF RTDHT systems. Stability analysis of an idealized two‐story shear frame with two DOFs is first performed to illustrate the proposed method. The delay‐dependent stability condition is presented for various structural properties, time delay, and integration time steps. Effects of delay compensation methods on stability are also investigated. Then, the proposed method is applied to analyze the delay‐dependent stability of a single shaking table RTDHT system with an 18‐DOF finite element numerical substructure, and corresponding RTDHTs are carried out to verify the theoretical results. Furthermore, the stability behavior of a finite element RTDHT system with two physical substructures, loaded by twin shaking tables, is theoretically and experimentally investigated. All experimental results convincingly demonstrate that the delay‐dependent stability analysis on the basis of the discrete‐time root locus technique is feasible. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
12.
A. K. Fedorenko 《Geomagnetism and Aeronomy》2010,50(1):107-118
Wave disturbances of the Neutral Atmosphere above the polar caps are studied based on the Dynamic Explorer 2 satellite measurements.
The characteristic spatial scales of these disturbances are 500— 600 km. Based on an analysis of the synchronous variations
in different parameters, these disturbances were interpreted as propagating acoustic gravity waves (AGWs). The mass-spectrometer
measurements of concentrations of individual atmospheric gases made it possible to determine the following AGW components:
density of the acoustic compression, thermobaric, and average kinetic energies. It has been found out that the average (during
the period) densities of the acoustic and thermobaric energies are approximately equal for polar AGWs. The results indicate
that the contribution of these waves to the energy of the polar upper atmosphere is considerable. 相似文献
13.
Aglika Savtchenko Rumjana Mitzeva Boryana Tsenova Staytcho Kolev 《Journal of Atmospheric and Solar》2009,71(12):1277-1286
Two sprite-producing mesoscale convective systems above the South-Western part of France are studied. Three sprite events during the first night and seven during the second night were captured. Except for two events, the sprites could be associated with causative positive cloud-to-ground (+CG) discharges in the stratiform region of the storm. The analysis of lightning activity reveals that in both nights sprites occurred when lightning activity decreased rapidly and the ratio of +CGs to the total number of CGs decreased slightly. The average peak current of sprite-producing lightning was lower than 60 kA, in agreement with other observations. The delay times of sprites to their SPCGs varied from 57 to 140 m s and no correlation between events’ delay and shape was established. 相似文献
14.
Artificial light at night: implications for early life stages development in four temperate freshwater fish species 总被引：1，自引：0，他引：1
Anika Brüning Franz Hölker Christian Wolter 《Aquatic Sciences - Research Across Boundaries》2011,73(1):143-152
Flora and fauna have both evolved under a natural cycle of light and dark. But especially in urban areas, the night is now
increasingly disturbed by artificial light. Many traits and behaviours in fish are triggered by a circadian clock, for example
hatching and swim bladder inflation, which predominantly take place at dusk or night. As lighting becomes brighter and extends
farther into rural areas, the distinction between day and night becomes increasingly blurred. Therefore, the loss of diurnal
trigger by artificial light at night was hypothesized having deleterious effects on these traits and impact fish reproduction.
To assess these effects, eggs of four native freshwater fishes, Eurasian perch Perca fluviatilis, roach Rutilus rutilus, bleak Alburnus alburnus and chub Leuciscus cephalus, were incubated under two different light conditions: a photoperiod of 14 h light:10 h darkness (LD) and continuous illumination
(LL). The time to hatch and swim bladder inflation was recorded. The species showed inconsistent reactions to the light treatments.
In roach and bleak, the time to 50% hatch was longer in LL, whereas continuous lighting had an accelerating effect in chub.
Incubation in LL elongated the hatching period in perch and roach and, in perch, the onset of darkness seemed to trigger hatching.
The swim bladder inflation was significantly promoted by continuous light in chub and bleak but was not affected in roach.
In conclusion, nocturnal artificial illumination could have an effect on hatching and initial swim bladder filling by masking
the day–night-change and thereby diminish the trigger effect. However, the reactions were species specific and the increase
in variation indicated a lack of diurnal triggering, whilst a general deleterious effect of artificial light at night has
not been identified on early life stages. 相似文献
15.
基于声发射参量的煤样损伤模型研究 总被引：1，自引：0，他引：1
在单轴压缩下煤样损伤模型基本原理的基础上,推导出了基于声发射参量的煤样损伤模型。以原煤为研究对象,在单轴压缩下,对煤样进行声发射实验,验证了基于声发射参量的煤样损伤模型在煤样破坏前是可行的;分析了在单轴压缩下的声发射特性,并提出了基于＂归一化＂声发射累计计数的损伤变量,得到了在单轴压缩下煤样的应变—损伤方程和煤样的一维损伤本构方程。研究结果表明：声发射参量能够反映煤样内部原生裂隙的压密及新裂隙的产生、扩展、贯通等演化过程;基于声发射参量的煤样损伤模型是合理的,反映了声发射事件数和煤样损伤之间的对应关系;单轴压缩下的煤样损伤演化过程,可分为初始损伤阶段、损伤稳定演化和发展阶段、损伤加速发展阶段和残余损伤阶段4个阶段。 相似文献
16.
Integrating process‐based flow and temperature models to assess riparian forests and temperature amelioration in salmon streams 下载免费PDF全文
下载免费PDF全文 Luca Fabris Iain Archibald Malcolm Willem Bastiaan Buddendorf Chris Soulsby 《水文研究》2018,32(6):776-791
The importance of riparian tree cover in reducing energy inputs to streams is increasingly recognized in schemes to mitigate climate change effects and protect freshwater ecosystems. Assessing different riparian management strategies requires catchment‐scale understanding of how different planting scenarios would affect the stream energy balance, coupled with a quantitative assessment of spatial patterns of streamflow generation. Here, we use the physically based MIKE SHE model to integrate simulations of catchment‐scale run‐off generation and in‐stream hydraulics with a heat transfer model. This was calibrated to model the spatio‐temporal distribution of hourly stream water temperature during warm low flow periods in a Scottish salmon stream. The model was explored as a “proof of concept” for a tool to investigate the effects of riparian management on high stream water temperatures that could affect juvenile Atlantic salmon. Uncertainty was incorporated into the assessment using the generalized likelihood uncertainty estimation approach. Results showed that by decreasing both the warming (daylight hours) and the cooling (night‐time hours) rates, forest cover leads to a reduction of the temperature range (with a delay of the time to peak by up to 2 hr) and can therefore be effectively used to moderate projected climate change effects. The modelling presented here facilitated the quantification of potential mitigating effects of alternative riparian management strategies and provided a valuable tool that has potential to be utilized as an evidence base for catchment management guidance. 相似文献
17.
18.
Experimental study on the performance of an azimuthal acoustic receiver sonde for a downhole tool 下载免费PDF全文
下载免费PDF全文 Xiaohua Che Wenxiao Qiao Xiaodong Ju Jinping Wu Baiyong Men 《Geophysical Prospecting》2017,65(1):158-169
A new azimuthal acoustic receiver sonde with a body and corresponding circuits was designed for a downhole tool. The 64‐sensor receiver sonde holds eight receiver stations that can be combined into at least 64 three‐sensor receiver subarrays. As a result, the receiver sonde can use different sensor combinations instead of different transducer types to produce multiple modes, including a phased azimuthal reception mode and conventional monopole, dipole, and quadruple modes. Laboratory measurements were conducted to study the performance of the azimuthal acoustic receiver sonde for a downhole tool, and the experimental results indicate that the receiver sonde provides a consistent reception performance. Individual sensors receive similar time‐domain waveforms, and their corresponding frequency bands and sensitivities are consistent within the measurement errors of around 5%. The direction of the reception main lobe is approximately parallel to its exterior normal direction. In addition, a receiver subarray with three sensors receives waveforms that have higher energy and narrower beamwidths. For individual sensors, the angular width of the dominant reception lobe is 191.3° on average, whereas that of the individual receiver subarrays is approximately 52.1° on average. The amplitude of the first arrival received by the receiver subarray centred at the primary sensor directly pointing to the source is approximately 2.2 times the average amplitude of the first arrivals received by the other receiver subarrays in the same receiver station. Thus, the maximum amplitude of the waveforms received by the receiver subarrays can be used to determine the direction of the incident waves. This approach represents a promising method for determining the reflector azimuth for acoustic reflection logging and three‐dimensional acoustic logging. 相似文献
19.
Cetacean mass stranding events associated with naval mid-frequency sonar use have raised considerable conservation concerns. These strandings have mostly involved beaked whales, with common pathologies, including "bubble lesions" similar to decompression sickness symptoms and acoustic traumas. However, other cetacean species have also stranded coincident with naval exercises. Possible mechanisms for the strandings include a behavioral response that causes deep divers to alter their diving behavior, which then results in decompression sickness-like impacts. Current mitigation measures during military exercises are focused on preventing auditory damage (hearing loss), but there are significant flaws with this approach. Behavioral responses, which occur at lower sound levels than those that cause hearing loss, may be more critical. Thus, mitigation measures should be revised. A growing number of international bodies recognize this issue and have urged increasing scrutiny of sound-producing activities, but many national jurisdictions have resisted calls for increased protection. 相似文献
20.
用1957~2006年间515个主相单步发展的磁暴事件,分析东亚扇区4个中低纬台站的电离层扰动类型及电离层暴开始时间,得到该地区电离层暴随纬度、季节和地方时的分布规律.研究表明,中纬区负暴明显,低纬区正暴明显;夏季负暴比正暴多,冬季正暴比负暴多,春秋季正负暴分布表现出明显的纬度差异.在东亚扇区,中纬区负暴开始时间主要分布在夜间及清晨时段,且在正午至午后时段极少发生.低纬区正暴开始时间主要发生在白天时段,且在夜间18~21 LT时段也易发生正暴.中低纬电离层正相暴平均延迟时间在10 h以内,负相暴平均延迟时间在10 h以上,且中纬区延迟时间明显比低纬区短.电离层暴延迟时间与磁暴主相开始时间对应的地方时很相关,正相暴对白天发生的磁暴比对晚上发生的磁暴响应快些,而负相暴正好相反.但电离层暴延迟时间与磁暴强度之间并没有十分明显的依赖关系. 相似文献