SDSS J131339.98+515128.3: a new gravitationally lensed quasar selected based on near-infrared excess     

Eran O. Ofek  Masamune Oguri  Neal Jackson  Naohisa Inada  Issha Kayo 《Monthly notices of the Royal Astronomical Society》2007,382(1):412-418

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Solute distribution in porous rhyolite as evaluated by sequential centrifugation     

Tadashi Yokoyama  Satoru NakashimaTakashi Murakami  Lionel MercuryYusuke Kirino 《Applied Geochemistry》2011,26(8):1524-1534

Pore water in a porous rhyolite, having a porosity of 27% and pore radii ranging from >25 μm to 0.008 μm, was centrifugally extracted stepwise with increasing centrifugal speed to examine the potential variations of the compositions of pore water and their relationships to reaction and transport occurring in the rock. The rock was soaked for from 1 h to 7 days in an aqueous solution prior to centrifugation. To evaluate the effect of adsorption under minimum effect of dissolution, Li⁺ and Br⁻ were added to the solution as tracer ions. As centrifugal speed increased, water was extracted in order of large to small pores and the thickness of residual water film became thinner. The concentrations of ions dissolving from the rock (Na⁺, K⁺, Ca²⁺, etc.) after 7 days of immersion were relatively constant in pores of 1-10 μm radii and exponentially increased by 3-100 fold with decreasing pore radius to 0.1 μm. These ions are dissolved from the rock and transported toward the exterior of the rock by diffusion. The calculation using a reactive-transport equation showed that the observed concentration changes reflect the change in solute distribution profile with pore size. The concentration of Si after 7 days of immersion was approximately constant or slightly decreased with increasing centrifugal speed, which appears to be controlled by the solubility. The concentration of Li⁺ decreased with increasing centrifugal speed after 1 h of immersion but the trend changed after 7 days of reaction. Initial behavior of Li⁺ is explained by adsorption on pore walls, and the change of trend is explained by desorption of that previously adsorbed, slight amounts of dissolution, and inflow from the outside of the rock. The change in concentration of Br⁻ with increasing centrifugal speed was small, probably because Br⁻ was not adsorbed on the surfaces. The sequential centrifugation thus provides information on the solute distribution associated with reaction and transport occurring in rock pores.  相似文献   

冻结法施工旁通道的冻土压力现场监测方法     

林萍  叶冠林  陈楠  王建华  桥本正 《岩土力学》2011,32(8):2555-2560

冻结法广泛用于盾构隧道的旁通道施工,但设计上对于冻结引起的作用在隧道上的冻胀力还没有明确取值方法,其主要原因之一是缺乏现场测量数据。以上海长江隧道的旁通道施工为背景工程,采用新型土压力计监测。首先介绍了PAD式土压力计的基本特征和安装方法,然后介绍了自动数据采集和测点设置原则,接着通过实例重点说明电缆保护的重要性和保护措施。上述监测工作保证了全部5个土压力计的正常工作,并获得了有效的实测数据。数据显示,冻结工法造成的最大荷载增量远小于预期值,这主要是由于施工上设置了泄压孔,从而减少了作用在管片上的冻胀力  相似文献   

Microbial community respiration and structure of dead zone sediments of Omura Bay, Japan   总被引：1，自引：0，他引：1  

Minoru Wada  Shotaro Suzuki  Tadashi Nara  Yu Umezawa  Motohiro Shimanaga  Kazumi Matsuoka  Hideaki Nakata 《Journal of Oceanography》2012,68(6):857-867

Monitoring sediment microbial community metabolism and structure is instrumental to understanding biogeochemical processes in and ecological impacts on bottom environments. The aim of this study was to determine potential community respiration and to reveal community dynamics of the microorganisms in the dead zone sediments of Omura Bay, Japan. The bay is highly enclosed and develops severe hypoxia in the central regions every summer. We collected sediment core samples from the center of the bay during hypoxia, estimated sediment oxygen consumption by using an adapted in vivo electron transport system activity (in vivo ETSA) assay, enumerated abundance of bacteria, and analyzed bacterial community structure by automated ribosomal intergenic spacer analysis. Higher ETSA and bacterial diversity were found in upper sediments (within 3?cm depth) from the center than the fringe of the bay. Sediment bacterial community structure of the bay center was distinct from that of the fringe. From these results, upper sediment in the dead zone of Omura Bay was characterized by (1) greater community respiration and (2) greater diversity of bacterial components compared with the non-hypoxic sediment of the bay fringe. These characteristics have important implications for understanding the interaction between microbial communities and the development of hypoxia in Omura Bay.  相似文献   

Models for the Origin of the Quadrantids     

Tomoyasu Tanigawa  Shinsuke Abe  Masateru Ishiguro  Tadashi Mukai 《Earth, Moon, and Planets》2010,106(1):55-65

We present two scenarios for production of the Quadrantid stream based on two different models for its origin: the extinct model in which 2003EH1 was an active comet that released the dust particles during past 5000 years, stopping its activity abruptly in AD 1488; and the split model; in which a catastrophic disruption of an asteroid at AD 1488 released a large number of dust particles in a single event. We calculate the orbital evolution of test particles released in both cases and derive the resulting size distribution of surviving meteoroids in the current Quadrantid stream in the form of s ^−α ds, where s denotes the radius of a meteoroid. We find α = 3.1 in the extinct model and 2.0 in the split model. In addition, the radius of the surviving meteoroids is derived as s >10 μm in the both models. We propose, based on our estimation of the infrared color ratio for the Quadrantid stream derived from both models, that infrared observations of the Quadrantid stream may determine which origin model is more reasonable.  相似文献   

Dimensions of long‐nosed Chimaera Harriotta Raleighana from New Zealand     

J. A. F. Garrick  T. Inada 《新西兰海洋与淡水研究杂志》2013,47(2):159-167

The proportional dimensions of 66 adult specimens of Harriotta raleighana Goode & Bean, 1895 (Holocephali: Rhinochimacridae) from New Zealand are summarised; in both sexes there is considerable variation in proportions. Within the size range of the sample, the snout region of males is proportionately longer than that of females, and growth of the snout is negatively allometric in both sexes. Meagre data suggest that similar sexual dimorphism and allometry occur in North Atlantic specimens, though very large and very small specimens do not fit an extrapolation of the New Zealand data. None of the New Zealand males has the snout tip upturned and armed with large rounded knobs as described for North Atlantic males.  相似文献   

End bearing capacity comparison of screw pile with straight pipe pile under similar ground conditions     

Adnan Anwar Malik  Jiro Kuwano  Shinya Tachibana  Tadashi Maejima 《Acta Geotechnica》2017,12(2):415-428

In the present study, the end bearing capacity of screw and straight pipe pile under similar pile tip area and ground conditions were investigated. The effect of increasing overburden pressure was also considered in this research. Pile load tests on close-ended screw and straight pipe piles were conducted in the small scale. Dry Toyoura sand was used to develop the model ground. The sand was compacted at relative density of 70, 80 and 92 %. It was observed that in case of straight pipe pile, load settlement curve plunges downward without increase in load around settlement equals to 10 % of pile tip diameter, whereas in case of screw pile, the load settlement curve plunges around settlement equals to 15 % of pile tip diameter. Moreover, the screw piles having helix-to-shaft diameter ratio 2–4.1 showed 2–12 times higher end bearing capacity than straight pipe piles with similar pile shaft diameter. It was also observed from the test results that the end bearing capacity of single-helix screw pile was in average 16.25 % less than straight pipe pile with similar pile tip area and ground conditions irrespective of the effect of increasing overburden pressure.  相似文献   

Infrared photometry of Venus: Variation during 10 years?     

Tetsuya Nagata  Shuji Sato  Tadashi Mukai  Sonoyo Mukai 《Icarus》1985,63(2):217-221

The infrared flux of Venus has been observed with a narrowband filter (λ = 3.6 μm, Δλ = 0.08 μm) from 1982 through 1984, covering a range of the phase angle α from 27 to 94°. Normalized values of flux at the Venus-Earth distance of 1 AU were (4.0–5.4) × 10^?17W/cm²/cm^?1 and the α dependence of the data is rather weak. Furthermore, when the evening terminator of Venus was seen, lower values of flux were obtained in contrast with higher values at the morning terminator. The α dependence is quite different from that of J.V. Martonchik and R. Beer (1975, J. Atmos. Sci.32, 1151–1156). Since we cannot find any significant problem in the two observational methods, the difference might suggest an intrinsic time variation of haze particles during these 10 years in the upper haze layer of the Venus cloud.  相似文献   

Monitoring of DSP toxins in small-sized plankton fraction of seawater collected in Mutsu Bay,Japan, by ELISA method: relation with toxin contamination of scallop     

Imai I  Sugioka H  Nishitani G  Mitsuya T  Hamano Y 《Marine pollution bulletin》2003,47(1-6):114-117

Monitorings were conducted on DSP toxins in mid-gut gland of scallop (mouse assay), cell numbers of toxic dinoflagellate species of Dinophysis, and diarrhetic shellfish poisoning (DSP) toxins in small-sized (0.7-5 microm) plankton fraction of seawater collected from surface (0 m) and 20 m depth at a station in Mutsu Bay, Aomori Prefecture, Japan, in 2000. A specific enzyme-linked immunosorbent assay (ELISA) was employed for the analysis of DSP toxins in small-sized plankton fraction using a mouse monoclonal anti-okadaic acid antibody which recognizes okadaic acid, dinophysistoxin-1, and dinophysistoxin-3. DSP toxins were detected twice in the mid-gut gland of scallops at 1.1-2.3 MU (mouse units) g(-1) on 26 June and at 0.6-1.2 MU g(-1) on 3 July, respectively. Relatively high cell densities of D. fortii were observed on 26 June and 11 September, and may only contribute to the bivalve toxicity during late June to early July. D. acuminata did not appear to be responsible for the toxicity of scallops in Mutsu Bay in 2000. ELISA monitoring of small-sized plankton fraction in seawater could detect DSP toxins two weeks before the detection of the toxin in scallops, and could do so two weeks after the loss of the bivalve toxicity by mouse assay. On 17 July, toxic D. fortii was detected at only small number, <10 cells l(-1), but DSP toxins were detected by the ELISA assay, suggesting a presence of other toxic small-sized plankton in seawater. For the purpose of reducing negative impacts of DSP occurrences, monitorings have been carried out hitherto on DSP toxins of bivalve tissues by mouse assay and on cell densities of "toxic" species of Dinophysis. Here we propose a usefulness of ELISA monitoring of plankton toxicity, especially in small-sized fraction, which are possible foods of mixotrophic Dinophysis, as a practical tool for detecting and predicting DSPs in coastal areas of fisheries grounds of bivalve aquaculture.  相似文献   

Pyroxenes from the Beaver Bay gabbro complex of Minnesota     

Prof. Tadashi Konda 《Contributions to Mineralogy and Petrology》1970,29(4):338-344

Although the Beaver Bay ferrogabbro is a small-scale layered intrusion, Ca-rich pyroxenes show a strong iron enrichment during fractionation, ranging from augite (Mg₃₈Fe₂₄ Ca₃₈) to ferrohedengergite (Mg₁₀Fe₄₈Ca₄₂). Ca-poor pyroxenes from intermediate pigeonite (Mg₃₉Fe₅₀Ca₁₁) to ferriferous pigeonite (Mg₂₇Fe₆₅Ca₈) occur as intercumulus minerals. The pyroxenes from the non-layered Beaver River gabbro are included in the overall pyroxene fractionation trend of the Beaver Bay gabbro complex. The pyroxene trend of the Beaver Bay gabbro complex is similar to those of the Skaergaard and Bushveld; however, there is a slight difference in that the Ca-rich pyroxenes of Beaver Bay (having Mg content over 30%) are slightly richer in Ca than either the Skaergaard or Bushveld augites.  相似文献