Optical properties of solid and liquid sulfur at visible and infrared wavelengths     

R. Sasson  R. Wright  E.T. Arakawa  B.N. Khare  Carl Sagan 《Icarus》1985,64(3):368-374

Knowledge of the optical constants of elemental sulfur has potential applications to Venus, Jupiter, Io, Amalthea, and the Earth. The real part, n, of the index of refraction of liquid sulfur (at 133°C) and of solid orthorhombic sulfur (at 25°C) for the wavelength range 0.4–2.0 μm were measured ellipsometrically. The imaginary part, k, of the refractive index of liquid sulfur was obtained by transmittance measurements at the same temperature and wavelength range. The reflectance of semi-infinite slabs of solid and liquid sulfur is calculated using the measured n and k values. We confirm that sulfur melts on Io would be classified as “black” by the Voyager imaging system.  相似文献   

A spectroscopic study of the microorganism model of interstellar grains     

S. Yabushita  K. Wada  T. Takai  T. Inagaki  D. Young  E. T. Arakawa 《Astrophysics and Space Science》1986,124(2):377-388

The microorganism model of interstellar grains is investigated by spectroscopy from the infrared (IR), visible to the ultraviolet (UV) wave regions.E. coli, yeast and spores ofBacillus subtilis exhibit absorption bands at =3.1 and 9.7 m; they also exhibit several absorptions at 68 m which are in agreement with the observed IS extinction curves.To obtain the extinction curves in the visible and UV regions, dry films of microorganism are prepared on a MgF₂ plate or synthesized quartz plate and their spectra measured. In the wavelength region 190400 nm, conventional spectrophotometers are adopted for the measurement. The extinction curve of the film ofE. coli is similar to the observed IS curve.For the wave-range 100<<400 nm, a vacuum UV spectrometer is adopted to avoid absorptions due to O₂ in the atmosphere. The extinction spectra by this method are in agreement with the result obtained by the conventional method where comparison is possible. The extinction curves ofE. coli and yeast are such that they incrase towards the short wavelength and exhibit a peak at -190 nm, which is different from the well-known IS peak at =220 nm. It remains to be seen whether interstellar low temperatures (1040 K) can shift the peak position in the extinction curve of biochemical materials.  相似文献   

Predictability of Interannual Variability in the Kuroshio Transport South of Japan Based on Wind Stress Data over the North Pacific   总被引：1，自引：3，他引：1  

Kiyoshi Tanaka  Motoyoshi Ikeda  Yukio Masumoto 《Journal of Oceanography》2004,60(2):283-291

It is expected that a roughly two-year forecast of the Kuroshio transport variation can be made from a past record of wind stress data over the ocean, since it takes nearly ten years for the first-mode baroclinic Rossby wave to traverse the entire basin in the midlatitude North Pacific (∼30°N). We therefore investigated the predictability using an ocean general circulation model driven by the wind stress data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis. Referring to a hindcast experiment as the control run, we carried out fifteen forecast experiments, the initial conditions of which are taken from the hindcast experiment at intervals of two years during the period from the end of 1969 to the end of 1997. Each of the forecast experiments is driven only by wind stress in the year preceding each experiment. The forecasted Kuroshio transport anomaly south of Japan agrees better with the hindcasted one during the first two years of the forecast in most cases. In some cases, however, significant disagreements occur, most of which are likely due to larger unpredictable variations caused by wind stress anomalies near Japan. At the end of forecast year 2, the anomaly correlation coefficient is about 0.7, and rms of the forecast error is smaller than rms of the hindcasted anomaly. These results indicate that the prediction of the interannual variability in the Kuroshio transport could be made two years in advance at a statistically significant level. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Measurements of directional spectrum of wind waves using an array of wave detectors Part II. Field observation     

Yukio Fujinawa 《Journal of Oceanography》1975,31(1):25-42

The directional spectrum of wind waves was observed using seven wave gauges at the marine observation tower. Directional spectrum was calculated by the method described inFujinawa (1974 a) which assures the high directional resolving power. Under the nearly uniform condition of the wind the process of wave development was studied by the use of the data of the directional spectrum. The analysis revealed that, 1) the mean wave direction does not necessarily coincide with the wind direction, 2) the directional spreading is much narrower than hitherto reported, 3) the growth rate is closely proportional to the square of cosine of the angle between the wave direction and the wind direction, 4) the resonancetype wave-wave interaction plays only minor role in the process of wave development for any wave component in the earlier stage of development and for the most rapidly developing component in the main stage of development.  相似文献   

Growth and gonad production of the sea urchin Hemicentrotus pulcherrimus in the fucoid bed and algal turf in northern Japan     

Yukio Agatsuma  Nobuyasu Nakabayashi  Nobuaki Miura  & Kazuya Taniguchi 《Marine Ecology》2005,26(2):100-109

To clarify the differences in the growth and gonad size of the sea urchin Hemicentrotus pulcherrimus among algal sere, the study was conducted in June and July, and September 1998 at three fucoid beds in Oga and at three algal turfs in Hachimori, Akita Prefecture in northern Japan. The most rapid growth was observed in a large perennial fucoid bed at the climax stage. Growth in a small perennial Chondrus ocellatus‐dominated bed in algal turfs in the seral stage was then high. The slowest growth was observed in the small perennial Dictyopteris divaricata‐ and Laurencia spp.‐dominated beds which are known to possess chemicals which act as feeding deterrents against the sea urchins. The gonad index (gonad wet weight × 100/body wet weight) at a fucoid bed was high where standing crops exceeded 3 kg·m^?2. The gonad index in the Laurencia bed was lower than those at fucoid beds. These results suggest that growth and gonad production are affected by algal sere and differ among species of small perennial algae in the seral stage with or without chemical defense.  相似文献   

海洋生物-光学算法研究──南黄海叶绿素浓度的估算     

傅克忖  曾宪模  李宝华  曾晓起  荒川久幸 《海洋与湖沼》1997,28(3):238-244

根据１９９５年９月中日合作南黄海现场观测资料，对南黄海生物－光学算法进行研究。首先对南黄海现场多光谱反射比数据进行因子分析，解反射比协方差矩阵的特征问题；解出特征值和对应的特征向量，求出主因子，然后建立叶绿素α对主因子的多元线性回归方程，并对算法进行回报和预报检验。计算结果表明，该算法具有较高精度，同时也显示出天气条件对估算精度产生较大影响。  相似文献   

海洋生物-光学算法研究──南黄海叶绿素浓度的估算     

傅克忖  曾宪模  李宝华  曾晓起  荒川久幸 《海洋与湖沼》1997,28(3):238-244

根据1995年9月中日合作南黄海现场观测资料，对南黄海生物一光学算法进行研究。首先对南黄海现场多光谱反射比数据进行因子分析，解反射比协方差矩阵的特征问题；解出特征值和对应的特征向量，求出主因子，然后建立叶绿素a浓度对主因子的多元线性回归方程，并对算法进行回报和预报检验。计算结果表明，该算法具有较高精度，同时也显示出天气条件对估算精度产生较大影响。  相似文献   

Surface interpolation by a spline technique     

Yukio Oonishi 《Journal of Oceanography》1975,31(6):259-264

A new method for a surface interpolation is proposed, in which the concept of splines under tension is applied. It is useful for the two-dimensional data analysis based on the non-linear fundamental equations in the physical oceanography.  相似文献   

The content of selenium and its chemical form in sea water   总被引：1，自引：0，他引：1  

Yukio Sugimura  Yoshimi Suzuki  Yasuo Miyake 《Journal of Oceanography》1976,32(5):235-241

By using the new fluorometric method of determination of the total selenium ( Se), Se (IV) and Se (VI), the content of selenium in sea weter was determined in the western North Pacific. Results showed that the content of Se in surface water ranged from 0.06 to 0.12g l^–1, while in deeper layers, the content increased to 0.20g l^–1. It was found that Se (IV) showed rather uniform distribution with depth, while Se (VI) increased with depth to about three times that in the surface. The ratio of Se (IV) to the Se ranged from 0.5 to 0.8 in the surface and 0.4 to 0.6 in the deep. The coexistence of the hexa- and tetravalent ions of selenium was confirmed both in surface and deep layers. Some results of observations on the content of selenium in the coastal areas of Japan were also reported.  相似文献   

A new fluorometric method of analysis of selenium in sea water     

Yukio Sugimura  Yoshimi Suzuki 《Journal of Oceanography》1977,33(1):23-29

A new method of determination of selenium and separation of Se(IV) and Se(VI) in sea water is described. The selenium is determined by fluorometric method using Se-DAN complex in cyclohexane media. Prior to the fluorometric determination, Se(IV) is separated from sea water by means of Se(IV)-DDTC complex which is adsorbed on the macroreticular resin. As to the separation of the total selenium from sea water sample, the reduction and coprecipitation method is used. Se(VI) is determined with the same method as used for the total selenium after the separation of Se(IV). The average recoveries are 92.5±1.3% for Se(IV) and 97.4±0.9% for Se. The standard deviation of analytical results is below 10%.  相似文献