The Doppler Effect and Spectral Energy Distribution of Blazars   总被引：2，自引：0，他引：2  

Guang－ZhongXie  Ben－ZhongDai 《中国天文和天体物理学报》2001,1(3):213-220

The relativistic beaming model is adopted to discuss quantitatively the observational differences between radio-selected BL Lac objects (RBLs) and X-ray-selected BL Lac objects (XBLs), and between BL Lac objects and flat spectrum radio quasars (FSRQs). The main results are the following:(1) In the Doppler corrected color-color(αro^in-αox^in) diagram,XBLs and FSRQs occupy separated regions, while RBLs bridge the gap between them. These properties suggest that similar intrinsic physical processes operate in all the objects under a range of intrinsic physical conditions. (2) Our results are consistent with the results of Sambruna, Maraschi and Urry (1996) from other methods. We show the αxox introduced by Sambruna to be a good index for describing the energy distribution because it represents the intrinsic energy distribution and includes the Doppler correction. (3)The Doppler effect of relativistic beaming is the main mechanism, and the physical differences(such as magnetic fields, electron energies) are also important complementary factors for understanding the relation between XBLs and RBLS.  相似文献   

类星体红移分布△ln（1＋z）＝0．205周期性的一种解释     

胡岳东  周又元  戴和俊 《天文学报》1994,(3)

根据红移定义１＋ｚ＝λｉ／λ０ｉ，我们认为类星体红移分布ｌｎ（１＋ｚ）周期性受两个因素影响。首先，决定类星体红移的主要线（如Ｌα１２１６，ＣＩＶ１５４９，ＣＩＩＩ１９０９，ＭｇＩＩ２７９８，ＮｅＶ３４２６，ＯＩＩ３７２７，ＮｅＩＩＩ３８６８，Ｈγ４３４０，Ｈβ４８６１，ＯＩＩＩ５００７）固有波长可能构成０．２０５的周期性；另外，这些谱线的观测波长进入一定光学窗口对红移有一定限制，在一定条件下，它正好在某些红移出现峰值，并与ｌｎ（１＋ｚ）＝０．２０５预言峰值一致。我们还在这两个基本考虑下进行模拟取样，发现有明显周期性，定量上证实了我们的基本考虑。本文是类星体红移分布的一种解释，它能说明为什么统计分布不同样品能得到不同的结论。进而，我们认为红移分布周期性不能成为内禀红移观点的观测支持。  相似文献   

40Ar/39 Ar isotopic ages of Qitianling granite and their geologic implications     

Yimao  Liu  Jifeng  Xu  Tongmo  Dai  Xianhua  Li  Xiguang  Deng  Qiang  Wang 《中国科学:地球科学(英文版)》2003,46(1):50-59

This paper has reported the first application of ⁴⁰Ar/³⁹ Ar dating to orthoclase from Qitianling granite. The resultant plateau ages yielded by three orthoclase specimens 2KL-17, 99LQ-2 and 2KL-31 (Note: The last one was taken from the part of granite which had been attributed to Cailing super-unit of the Indosinian Period by the former researchers) collected from the said granite are (139.57±2.79) Ma, (140.55±2.81) Ma and (144.91±2.90) Ma respectively. The above-mentioned ages represent the closed ⁴⁰Ar/³⁹ Ar age of the orthoclase. The consistency in age dating results, the similarity in geochemical characteristics and rock textures, and the NW-SE orientation of orthoclase phenocrysts almost throughout the granite, provide evidence for the intimate relationship between the Furong super-unit and the Cailing super-unit that form the main part of the granite, suggesting that they are products of comagmatic conjugate differentiation during the Late Jurassic. This paper also makes a comparison between the Qitianling granite and the Qianlishan granite.

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短期线状集中分布地磁日变化感应电流异常机理初步解释——以2012年唐山4.8级地震为例     

姜楚峰  吴迎燕  冯志生  戴勇  孙君嵩  章鑫  冯丽丽  李军辉 《中国地震》2022,38(2):226-238

本文分析了2012年唐山4.8级地震前,震中附近出现的短期原地重现线状集中分布地磁日变化感应电流异常的时空变化特征,及其与地震、中-下地壳和上地幔高导层的关系,进一步证实了短期原地重现线状集中分布感应电流的走向与中-下地壳和上地幔高导层顶面界埋深走向一致,认为其机理可能是深部热流体的上涌导致壳幔高阻体出现带有上拱性质的拆离滑动,深部上涌的热流体和高导层内热流体侵入高导层内电阻相对较高的地区,高导层出现短时间高导电流通道,当地磁日变化感应电流扫描经过高导电流通道时,感应电流会呈线状集中分布于此,并基于趋肤效应分布于其顶面附近。由于重现异常是发生在震源下方中-下地壳和上地幔高导层的地震异常,且该异常不同于震源附近及其震源至地表的地震异常,因此对推进地震孕育与发生机理研究可能有一定作用。此外研究还发现,地震虽然主要位于重叠段的端部,但更有可能位于中-下地壳重叠段的端部,这一发现对日常震情跟踪中应用该异常确定未来地震位置有一定帮助。  相似文献   

Distribution characteristics and factors influencing microbial communities in the core soils of a seawater intrusion area in Longkou City,China     

Sang  Shilei  Dai  Heng  Hu  Bill X.  Huang  Zhenyu  Liu  Yujiao  Xu  Lijia 《Hydrogeology Journal》2022,30(6):1833-1845

Microbes live throughout the soil profile. Microbial communities in subsurface horizons are impacted by a saltwater–freshwater transition zone formed by seawater intrusion (SWI) in coastal regions. The main purpose of this study is to explore the changes in microbial communities within the soil profile because of SWI. The study characterizes the depth-dependent distributions of bacterial and archaeal communities through high-throughput sequencing of 16S rRNA gene amplicons by collecting surface soil and deep core samples at nine soil depths in Longkou City, China. The results showed that although microbial communities were considerably impacted by SWI in both horizontal and vertical domains, the extent of these effects was variable. The soil depth strongly influenced the microbial communities, and the microbial diversity and community structure were significantly different (p < 0.05) at various depths. Compared with SWI, soil depth was a greater influencing factor for microbial diversity and community structure. Furthermore, soil microbial community structure was closely related to the environmental conditions, among which the most significant environmental factors were soil depth, pH, organic carbon, and total nitrogen.

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顺层岩质边坡溃屈变形机制及失稳判定方法     

吴朋宇  张志红  戴福初  姚爱军 《吉林大学学报(地球科学版)》2022,52(2):517-525

溃屈型破坏是一种常见的顺层岩质边坡破坏模式,溃屈变形发展机制及失稳破坏的定量研究对滑坡工程勘查和防治指导十分重要。本文根据边坡的地质环境和力学作用机制,建立了三维受压板简化模型,其能够考虑岩层自身重力、地震力、静水压力的共同作用和岩体材料塑性变形的影响。基于弹塑性受压板稳定理论,利用能量法推导得到了边坡溃屈变形破坏的临界方程。对于溃屈型边坡的结构失稳和滑动失稳分别提出了相应的稳定性判定方法,并针对不同状态的边坡提出了相应的防治措施建议。以四川省甘孜藏族自治州巴塘县下归哇边坡为例,对所提判定方法的正确性进行了验证。计算结果表明,边坡的临界溃屈长度（a1）为483.8 m,说明下归哇边坡能够发生溃屈变形;现场勘查得知边坡实际溃屈长度（a′）为530.0 m,a′＞a1,可知边坡是稳定的。这与实际情况相吻合,由此证明本文所提出的判定方法可行。  相似文献   

Mechanical behaviors of conjugate-flawed rocks subjected to coupled static–dynamic compression     

Feng  Peng  Zhao  Jiachen  Dai  Feng  Wei  Mingdong  Liu  Bo 《Acta Geotechnica》2022,17(5):1765-1784

Conjugate flaws widely exist in rock masses and play a significant role in their deformation and strength properties. Understanding the mechanical behaviors of rock masses containing conjugate flaws is conducive to rock engineering stability assessment and the related supporting design. This study experimentally investigates the mechanical properties of conjugate-flawed sandstone specimens under coupled static–dynamic compression, thereby providing insight into how conjugate fractures interact to produce tracing tensional joints. Results indicate that the coupled compressive strength and the dynamic elastic modulus of conjugate-flawed rock specimens show remarkable loading rate dependence. For a fixed strain rate, the specimen with a static pre-stress equal to 60% of its uniaxial compressive strength has the highest coupled strength. Besides, both higher static pre-stress and strain rate can induce smaller mean fragment size and greater fractal dimension of the specimen, corresponding to a more uniform distribution of the broken fragments with smaller sizes. When the static pre-stress is lower than 80%UCS, the flawed specimen under a higher strain rate is characterized by higher absorbed energy. However, when the pre-stress equals 80%UCS, the value of the energy absorbed by the specimen in the dynamic loading process is negative due to the release of the preexisting considerable elastic strain energy input from the static pre-loading. As for the failure modes, cracks always penetrate the preexisting ipsilateral flaw tips to form anti-wing cracks. Under dynamic loading, the conjugate-flawed specimen generally shows tensile failure at a low strain rate, while the shear failure dominates at a high strain rate. In addition, based on progressive failure processes of the conjugate-flawed rock specimens, the evolution of tracing tensional joints in the field is discussed.

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Correction to: Laboratory testing and numerical simulation of properties and thermal-induced cracking of Eibenstock granite at elevated temperatures     

Wang  Fei  Konietzky  Heinz  Frühwirt  Thomas  Dai  Yajie 《Acta Geotechnica》2022,17(7):3141-3141

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Enhanced anisotropic bounding surface plasticity model considering modified spacing ratio of anisotropically consolidated clay     

Kang  Xiaosen  Liao  Hongjian  Huang  Qiangbing  Dai  Qian 《Acta Geotechnica》2022,17(6):2213-2233

Acta Geotechnica - The critical state of anisotropically consolidated clay is not well captured by the classical anisotropic bounding surface plasticity model without considering the real...  相似文献   

海上高—特高含水期稠油油藏提高采收率实验研究     

张伟  戴建文  王亚会  涂乙 《地质科技情报》2022,41(3):193-199

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