添加维生素B_（12）生产菌高密度培养褶皱臂尾轮虫的效果

阐述把维生素Ｂ１２生产菌添加到培养水中培养褶皱臂尾轮虫ＢｒａｃｈｉｏｎｕｓＰｌｉｃａｔｉｌｉｓ的买验。共１８株细菌分离于轮虫培养池，其中，有一株产维生素Ｂ１２的假单胞杆菌ＴＰ４对轮虫的生长繁殖有明显的促进作用。把ＴＰ４菌株培养后，加入到２Ｌ的烧杯和５００Ｌ的水槽中培养泰国Ｓ型轮虫时．在９ｄ（天）和６ｄ（天）中，轮虫密度从１２４～１３９和２４２～２８８个体／ｍｌ增殖到４，４１７～５，５４０和１，０１７～１，２５４个体／ｍｌ，分别比对照组增加了４～６及２～３倍。     

Observation of hydrogen peroxide concentrations in a Japanese red pine forest

In order to study the concentrations of hydrogen peroxide (H₂O₂) and the factors controlling its concentrations, we monitored concentrations of H₂O₂ and other gases such as sulfur dioxide, ozone, and NO _x as well as meteorological factors such as air temperature, relative humidity, and wind direction/speed during eight measurement periods from 2000 to 2002 in a Japanese red pine forest in Japan. The H₂O₂ concentrations ranged from below 0.01 to 1.64 ppb, and analysis of the diurnal variation in H₂O₂ concentration showed high concentrations around noon, and low concentrations in the morning and late afternoon. The H₂O₂ concentrations were high in early summer, when O₃ concentration, temperature, and solar radiation were high, and were low in fall, when O₃ concentration, temperature, and solar radiation were low. We propose that O₃ concentration affects the production of H₂O₂ in the monitored region during the period under study, but that high H₂O₂ concentrations were sometimes caused by the transport of polluted air from urban regions. H₂O₂ concentrations decreased remarkably when SO₂ concentrations increased by transported volcanic emission on Miyake Island. In the absence of the effects of SO₂, H₂O₂ concentrations increased with increasing O₃ concentration and temperature.     

Concentrations of metallic elements in long-range-transported aerosols measured simultaneously at three coastal sites in China and Japan

To determine the effects of long-range transport of aerosols from an upwind area in East Asia to a downwind area in Japan, we chemically analyzed aerosols collected simultaneously on Tuoji Island (Shandong Province, China), Fukue Island (Nagasaki Prefecture, Japan), and Cape Hedo (Okinawa Prefecture, Japan). We focused on changes in the metallic composition of PM_2.5 aerosols during long-range transport. The average mass concentrations of PM_2.5 at the three sites decreased in the order Tuoji Island > Fukue Island ≈ Cape Hedo (48.3 ± 4.5, 13.9 ± 1.5, and 13.2 ± 0.9 μg/m³, respectively). The fraction of coarse particles in total suspended particles estimated by (1–PM_2.5/TSP) was highest on Cape Hedo, indicating that the contribution of sea salts was increased by long-range transport of the aerosols over the ocean. Enrichment factor analysis revealed that at all three sites, Al, K, Ca, Mn, Fe, Co, Sr, and Ba originated from soil; whereas Cr, Ni, Cu, Zn, As, Mo, Ag, Cd, Sn, Sb, Tl, and P appeared to be of anthropogenic origin. Na was the most abundant element on Cape Hedo, indicating the addition of sea salts during aerosol transport. The V concentration was highest at Fukue Island, which was ascribed to V emission from ships. Sixty-one percent of the V on Fukue Island and 62% of the V on Cape Hedo were determined to have originated from ships, implicating of data obtained on dates during which backward trajectory analysis indicated that the same air mass passed over Tuoji Island, Fukue Island, and Cape Hedo in that order.     

Dynamics of elastically moored floating objects

The two-dimensional problem of wave transformation by, and motions of, moored floating objects is solved numerically as a boundary value problem by direct use of Green's identity formula for a potential function. The cross-sectional shape of the floating object, the bottom configuration and the mooring arrangements may be all arbitrary. For a given incident wave, the three modes of body motion, the wave system and mooring forces are all solved at the same time. A laboratory experiment is conducted to verify the theory. Generally good agreements between the theory and experiments are obtained as long as the viscous damping due to flow separation is small. A numerical experiment indicates that a conventional sluck mooring is to worsen the wave attenuation by a floating breakwater and that a properly arranged elastic mooring can considerably improve the wave attenuation by a floating breakwater.     

Effects of scattering and dust grain size on the temperature structure of protoplanetary discs: a three-layer approach

The temperature in the optically thick interior of protoplanetary discs is essential for the interpretation of millimetre observations of the discs, for the vertical structure of the discs, for models of the disc evolution and the planet formation, and for the chemistry in the discs. Since large icy grains have a large albedo even in the infrared, the effect of scattering of the diffuse radiation in the discs on the interior temperature should be examined. We have performed a series of numerical radiation transfer simulations, including isotropic scattering by grains with various typical sizes for the diffuse radiation as well as for the incident stellar radiation. We also have developed an analytic model including isotropic scattering to understand the physics concealed in the numerical results. With the analytic model, we have shown that the standard two-layer approach is valid only for grey opacity (i.e. grain size ≳10 μm) even without scattering. A three-layer interpretation is required for grain size ≲10 μm. When the grain size is 0.1–10 μm, the numerical simulations show that the isotropic scattering reduces the temperature of the disc interior. This reduction is nicely explained by the analytic three-layer model as a result of the energy loss by scatterings of the incident stellar radiation and of the warm diffuse radiation in the disc atmosphere. For grain size ≳10 μm (i.e. grey scattering), the numerical simulations show that the isotropic scattering does not affect the interior temperature. This is nicely explained by the analytic two-layer model; the energy loss by scattering in the disc atmosphere is exactly offset by the 'green-house effect' due to the scattering of the cold diffuse radiation in the interior.     

Measurements of gas and aerosol for two weeks in northern China during the winter–spring period of 2000, 2001 and 2002

Intensive measurements of gas and aerosol for 2 weeks were carried out at Qingdao (gas and aerosol in 2000, 2001 and 2002), Fenghuangshan (gas and aerosol in 2000 and 2001), and Dalian (aerosol in 2002) in the winter–spring period. High SO₂ episodes were observed on 18 January 2000 at both Qingdao and Fenghuangshan. According to back trajectory calculations and analysis of gaseous species, high SO₂ episodes were caused by local pollution and transport.Nitrate, sulfate and ammonium were the major species in PM_2.5. Mass fractions of NO₃⁻, nss-SO₄²⁻ and NH₄⁺ at Qingdao in 2002 were 10%, 12% and 5.5% for PM_2.5, respectively, which were higher than that of nss-Ca²⁺ (1%). Chemical compositions observed at Dalian and Fenghuangshan were similar to those at Qingdao. The mass ratio of nss-SO₄²⁻/SO₂ at Qingdao in winter was low (< 1.2), indicating that sulfate was probably produced by the slow oxidation of SO₂ in the gas phase and/or was transported from outside of Qingdao in winter. The equivalent ratio of NH₄⁺ to nss-SO₄²⁻ was 1.39, suggesting that ammonium sulfate was one of the major chemical compositions in PM_2.5. The NO₃⁻/SO₄²⁻ ratio at Qingdao was higher than that at remote places in East Asia. Gas and aerosol data obtained at Fenghuangshan were similar to data at Qingdao, suggesting that emissions from small cities may have a great influence on pollution in northern China.     

Oblique and near collision subduction, Sagami and Suruga Troughs —preliminary results of the French-Japanese 1984 Kaiko cruise, Leg 2

Leg 2 of the French-Japanese 1984 Kaiko cruise has surveyed the Suruga and the Sagami Troughs, which lie on both sides of the northwestward moving and colliding Izu-Bonin Ridge, the northernmost part of the Philippine Sea plate. The transition from the Nankai Trough to the Suruga Trough is characterized by northward decrease in width of the accretionary prism, in good agreement with the increasing obliquity between the through axis and the direction of the convergence, as the strike of the convergent boundary changes from ENE-NNE to south-north. South of the area, the southern margin of the Zenisu Ridge shows contractional deformations. This supports the interpretation made by the team of Leg 1 who studied the western extension of the area we studied, that it is an intra-oceanic thrusting of the ridge over the Shikoku Basin. In the Sagami Trough, where the relative motion is highly oblique to the plate boundary, active subduction is mostly confined in the east-west trending portions of the trough located south of the Boso Peninsula and along the lower Boso Canyon, near the TTT triple junction. In between, the present motion is mainly right-lateral along the northwest trending Boso escarpment. However, an inactive but recent (Pliocene to lower Pleistocene) accretionary prism exists south of the Boso escarpment, which suggests that the relative motion was more northerly than at present before about 1 Ma ago.     

Medium-scale traveling ionospheric disturbances observed by GPS receiver network in Japan: a short review

Medium-scale traveling ionospheric disturbances (MSTID) are wave-like perturbations of the ionospheric plasma with wavelengths of several hundred kilometres and velocities of several hundred metres per second. MSTID is one of the most common ionospheric phenomena that generally induce the perturbations of ionospheric total electron content (TEC) by ∼10¹⁶ electron/m², which corresponds to ∼54 ns (16.2 cm) delay at GPS L1 signal. In the past decade, several new characteristics on MSTIDs have been revealed by the TEC observations using the dense GPS receiver network in Japan. In this paper, we provide a short review of these new observations and summarize the morphological characteristics of MSTIDs in Japan.     

ICT-Based Remediation with Knowledge Information Management for Contaminated Groundwater

ICT-based remediation with knowledge information management is presented for the pump-and-treat method of contaminated groundwater. The usefulness of ICT is discussed for monitoring contaminants and groundwater level, transferring data between the remediation well and the remote remediation center, and decision support analysis for controlling the remediation well. A prototype system was developed and applied to field measurement. The prototype system performed reliably for ~600 days. As a decision support analysis, a fuzzy inference model is discussed. The membership functions were determined based on simple reliability theory. The effectiveness of the proposed method was assessed by numerical simulations. The simulation results suggest that the proposed method is likely to reduce the pumped quantity compared to PID control or an engineer’s empirical knowledge. Analysis results are also shown for cancer risks from contaminants and ground settlement risks due to excess pumping up of groundwater.     

Quasi-Static Strain and Stress Fields due to a Moment Tensor in Elastic–Viscoelastic Layered Half-Space

We derived explicit expressions in the time domain for 3-D quasi-static strain and stress fields, due to a point moment tensor source in an elastic surface layer overlying viscoelastic half-space under gravity. The expressions of strain in the elastic surface layer were directly obtained from the expressions of displacement in our previous paper. The conversion of strain into stress is easy, because the stress–strain relation of elastic material is linear. In the viscoelastic substratum, the expressions of strain were obtained by applying the correspondence principle of linear viscoelasticity to the associated elastic solution. The strain–stress conversion is not straightforward, as the stress–strain relation of viscoelastic material is usually given in a differential form. To convert strain into stress, we used an integral form of the stress–strain relation instead of the usual differential form. The expressions give the responses of elastic half-space at \( t = 0 \) , and the responses of an elastic plate floating on non-viscous liquid at \( t = \infty \) . The moment tensor is rationally decomposed into the three independent force systems, corresponding to isotropic expansion, shear faulting and crack opening, and so the expressions include the strain and stress fields for these force systems as special cases. As the first numerical example, we computed the temporal changes in strain and stress fields after the sudden opening of an infinitely long vertical crack cutting the elastic surface layer. Here, we observe that the stress changes caused by the sudden crack opening gradually decay with time and vanish at \( t = \infty \) everywhere. After the completion of stress relaxation, a characteristic pattern of shear strain remains in the viscoelastic substratum. Since the strain and stress fields at \( t = \infty \) can be read as the strain- and stress-rate fields caused by steady crack opening, respectively, this numerical example demonstrates the realization of a steady stress state supported by steady viscous flow in the asthenosphere, associated with steady seafloor spreading at mid-ocean ridges. For the second numerical example, we computed the temporal changes in strain and stress fields after the 2011 Tohoku-oki mega-thrust earthquake, which occurred at the North American-Pacific plate interface. In this numerical example, the stress changes caused by coseismic fault slip vanish at \( t = \infty \) in the viscoelastic substratum, but remain in the elastic surface layer. The coseismic stress changes (and also strain changes) in the elastic surface layer diffuse away from the source region with time, due to gradual stress relaxation in the viscoelastic substratum.