中国西北帕米尔东北缘的活动断裂研究   总被引：7，自引：0，他引：7  

傅碧宏  林爱明  狩野谦一  丸山正  郭建明 《新疆地质》2003,21(1):1-8

在卫星遥感图像的详细地质解译分析基础上，结合野外地质与地貌观察，对帕米尔东北缘山前与印度－亚欧大陆碰撞相关的活动断层进行了分析。研究结果指出，NW－NWW走向的断层主要表现为南倾逆冲断层，并伴随有强烈的右旋走滑分量。流经活动断层带的水系显示出右旋累积位错：小水系的水平位错量为4.0-20.0m，大河流的水平位错量达8－12km。沿断层带的上新世至早更新世地层也显示出一致的水平位错，位错量为8－12km。这些证明表明，帕米尔东南山前的NW－NWW走向的断层很可能开始于上新世末期至早更新世早期（2.2-3Ma)。研究结果首次厘定了帕米尔东北缘山前与向北逆冲相伴随的右旋走滑速率在第四纪期间达4.0-6.8mm/a。根据与现代地震活动相关的活断层分析，推测帕米尔东北缘山前7级以上地震重复周期为1000a左右。  相似文献   

Deformation structures in shale bed indicate flow direction of overlying Miocene subaqueous pyroclastic flow     

Kazuhiko Kano  Shun Nakano  Koji Mimura 《Bulletin of Volcanology》1988,50(6):380-385

Thrusts, pinch-and-swell structures and undulations are present within a 2-m-thick layered shale bed of Miocene age that is overlain by a rhyolite subaqueous pyroclastic flow deposit 2–3 m thick. The deformation structures were caused by loading and lateral compression by the subaqueous pyroclastic flow, probably analogous to those observed in layered muds deformed by a sand mass advancing across them. Prominent thrusts strike east-west and dip south, and the crests of undulations strike east-west, indicating that the subaqeuous pyroclastic flow moved northward.  相似文献   

SHRIMP U-Pb Zircon Age of the Inishi Migmatite around the Kamioka Mining Area, Hida Metamorphic Complex, Central Japan     

Masatoshi Sakoda    Takashi Kano  C. Mark Fanning  Takaaki Sakaguchi 《Resource Geology》2006,56(1):17-26

Abstract. SHRIMP U-Pb ages were determined on single zircons separated from the Inishi migmatite in the Kamioka mining area, Hida metamorphic complex, central Japan. Twenty one determinations were distributed within the age of 234.2±1.8 Ma, excluding one inner core of a grain. As the analyzed crystals were mostly euhedral igneous zircons, the age indicates the crystallization of zircons from granitic melt during the formation of Inishi migmatite. The age of ca. 234 Ma corresponded to the later stage of the major regional metamorphic event in the Hida complex, while the age of ca. 265 Ma determined in a grain suggested the inherited age of the earlier phase of the metamorphism.  相似文献   

国际全球变化研究发展态势文献计量评价   总被引：1，自引：0，他引：1  

张志强  王雪梅 《地球科学进展》2007,22(7):0-765

-全球变化研究是国际上地球系统综合研究的重大跨学科研究领域。随着全球环境问题的日益突出，国际上先后组织发起了全球环境变化研究的四大科学计划WCRP、IGBP、IHDP、DIVERSITAS及其组成的地球系统科学联盟ESSP，开展对全球变化和地球系统科学的研究。当前，全球变化问题不仅是科学界关注和研究的问题，也是政治界、经济界都关注的重大问题。 科技文献能够反映科学前沿的发展动态。对SCIE和SSCI数据库收录的全球变化研究文献进行统计，从文献计量学的角度，分析国际全球变化研究领域的发展态势，了解中国全球变化研究的国际影响力。可以看出：国际上全球变化研究的论文数量一直呈增长趋势，以地球科学多学科、生态学、环境科学、自然地理学、植物学等学科领域为主。中国自2000年以来在该领域的发文数量增长较快，特别是中国科学院的发文量已进入国际前列，但中国在该研究领域尚缺少高影响力的论文。  相似文献   

Investigation on the Performance of Pipe Roof Method Adjacent to the Underground Construction     

Ma  Peng  Shimada  Hideki  Sasaoka  Takashi  Hamanaka  Akihiro  Dintwe  Tumelo K. M.  Pan  Donjiang 《Geotechnical and Geological Engineering》2021,39(6):4677-4687

In this paper, the behaviour of the pipe roof method with different pipe roofs disposition schemes including the pipe roof gate system and L-shaped system is discussed in terms of ground settlement reduction in the condition of underground space construction adjacent to the existing structure by using numerical simulation method. Considering the construction sequences of parallel underground tunnels with rectangular cross sections, the appropriate parameters and ground response characteristics of the corresponding pipe roof methods are evaluated by the ground surface displacement. The results indicated that the construction impacts from new buildings can be reduced by the pipe roof method. However, the theoretical performance of pipe roofs is highly dependent on the spacing between two structures. Generally, the L-shaped system is more effective in case of the distance (D) that is less than or equal to 1/2 width of box culvert (R) under the condition of a new structure constructed nearby the existing building. When two structures are constructed simultaneously, the excavation and the construction of structures influence each other reciprocally. The conclusions could provide a reference for the pipe roof method with the application scenario of adjacent building protection.

  相似文献   

Purification of seawater contaminated with undegradable aromatic ring compounds using ozonolysis followed by titanium dioxide treatment   总被引：1，自引：0，他引：1  

Nakamura Y  Kobayashi F  Daidai M  Kurosumi A 《Marine pollution bulletin》2008,57(1-5):53-58

Treatment of aromatic ring compounds, 2,4-dichlorophenoxy acetic acid (2,4-D), 2,4,5-trichloro-phenoxy acetic acid (2,4,5-T), and bisphenol A, in the artificial seawater, i.e. Allen seawater, was carried out by ozonation and titanium dioxide (TiO2) photocatalyst treatment. Each compound was degraded and varnished within 30 min by only ozonolysis at pH 9.0 and at 20 degrees C, while the TOC value of each compound decreased gradually but reached almost constant value, i.e. about 70-80% of the initial value, at even 30 min of ozonation time. Ozonolysis (30 min of ozonation time) followed by TiO2 photocatalyst treatment (50h of reaction time) was a very effective method for decreasing the TOC values of aromatic ring compounds in the artificial seawater. In consequence, TOC values of 2,4-D, 2,4,5-T, and bisphenol A could be reduced to about 28, 21, and 34% of their initial values, respectively.  相似文献   

Primary productivity and solar radiation off Sanriku in May 1997     

Akihiro Shiomoto  Shinji Hashimoto  Takayuki Murakami 《Journal of Oceanography》1998,54(5):539-544

We measured the in situ primary production at four stations from the surface to 80 m off Sanriku in late May 1997. The depth-integrated daily primary production in the upper 80 m was estimated to be 391, 468, and 855 mgC m⁻²d⁻¹ in water from the Oyashio, and 336 mgC m⁻²d⁻¹ in the warm-core ring. The variation in the primary production was primarily due to the variation in phytoplankton activity (chlorophyll α-specific primary production). A combination of previous and present studies in water from the Oyashio and the warm-core ring suggested that phytoplankton activity is proportional to light intensity between 12 and 50 Ein m⁻²d⁻¹ which is close to the usual light condition (61–75 Ein m⁻²d⁻¹) off Sanriku in May and June. Light may be a limiting factor for phytoplankton off Sanriku in late spring and early summer.  相似文献   

Depositional and diagenetic history of limestones and dolostones of the Oligo‐Miocene Kujung Formation in the Northeast Java Basin,Indonesia     

Muhlash Hada Firman Syah  Akihiro Kano  Tsuyoshi Iizuka  Yoshihiro Kakizaki 《Island Arc》2019,28(6)

Lithological and geochemical features of platformal carbonates record the signatures of the global climates and the regional environmental settings and also reconstruct the diagenetic history and porosity evolution, which are essential to evaluate the potential of hydrocarbon reservoirs. This study investigates the platformal carbonates of the Oligo‐Miocene Krunji Formation of North East Java Basin, which are potentially significant hydrocarbon reservoirs. The carbonate sequence in a 283 m thick section at Kranji in East Java is subdivided into three lithological units: limestone unit 1, dolostone unit 2, and limestone unit 3, in ascending order. The strontium‐isotope ratios of well‐preserved calcite samples indicate the depositional period from Chattian (late Oligocene) to Burdigalian (early Miocene), which is consistent with ages of the foraminifer assemblages. Unit 1 consists of low‐porosity limestone, in which two horizons of subaerial exposure are recognized by the occurrence of red‐colored matrix and lower δ¹³C values. Unit 2 consists of dolomitic rock and exhibits coarse‐grained calcitic grains and cross‐stratified structure. Considering that this unit has been subject to dolomitization, the sediment of unit 2 was initially permeable and was likely deposited in a shoal setting. The overlying unit 3 of Aquitanian–Burdigalian age is characterized by a highly granular texture. High porosity and uniformly low δ¹³C and δ¹⁸O values indicate that Unit 3 was subjected to more intense meteoric diagenesis than the Chattian unit 1. This was likely a consequence of the Antarctic ice‐sheet expansion during the Oligocene/Miocene transition, which amplified sea level change. The unit 2 dolomite has high δ¹³C and δ¹⁸O values and a high ⁸⁷Sr/⁸⁶Sr ratio which resulted from the reflux of seawater into permeable the sediment body in middle‐late Miocene (Burdigalian Tortonian) following the deposition of unit 3. The porosity and permeability of the Kujung Formation were initially controlled by sedimentological processes, but largely modified by later diagenetic processes.  相似文献   

The XUV Doppler Telescope (XDT)     

Sakao  T.  Tsuneta  S.  Hara  H.  Shimizu  T.  Kano  R.  Kumagai  K.  Yoshida  T.  Nagata  S.  Kobayashi  K. 《Solar physics》1999,187(2):303-333

  相似文献   

High-Reflectivity Coatings for a Vacuum Ultraviolet Spectropolarimeter     

Noriyuki Narukage  Masahito Kubo  Ryohko Ishikawa  Shin-nosuke Ishikawa  Yukio Katsukawa  Toshihiko Kobiki  Gabriel Giono  Ryouhei Kano  Takamasa Bando  Saku Tsuneta  Frédéric Auchère  Ken Kobayashi  Amy Winebarger  Jim McCandless  Jianrong Chen  Joanne Choi 《Solar physics》2017,292(3):40

Precise polarization measurements in the vacuum ultraviolet (VUV) region are expected to be a new tool for inferring the magnetic fields in the upper atmosphere of the Sun. High-reflectivity coatings are key elements to achieving high-throughput optics for precise polarization measurements. We fabricated three types of high-reflectivity coatings for a solar spectropolarimeter in the hydrogen Lyman-\(\upalpha \) (Ly\(\upalpha \); 121.567 nm) region and evaluated their performance. The first high-reflectivity mirror coating offers a reflectivity of more than 80 % in Ly\(\upalpha \) optics. The second is a reflective narrow-band filter coating that has a peak reflectivity of 57 % in Ly\(\upalpha \), whereas its reflectivity in the visible light range is lower than 1/10 of the peak reflectivity (\(\sim 5~\%\) on average). This coating can be used to easily realize a visible light rejection system, which is indispensable for a solar telescope, while maintaining high throughput in the Ly\(\upalpha \) line. The third is a high-efficiency reflective polarizing coating that almost exclusively reflects an s-polarized beam at its Brewster angle of 68° with a reflectivity of 55 %. This coating achieves both high polarizing power and high throughput. These coatings contributed to the high-throughput solar VUV spectropolarimeter called the Chromospheric Lyman-Alpha SpectroPolarimeter (CLASP), which was launched on 3 September, 2015.  相似文献