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Debye and its modified models are widely used to explain the relaxation polarization process in dielectrics at present. However, such models require prior knowledge of the number of polarization branches in them, so it is difficult to build an equivalent circuit model that matches the actual characteristics of relaxation polarization. Given this issue, a new method is proposed to analyze the relaxation polarization process in dielectrics by the distribution of relaxation time (DRT). In this article, cross-linked polyethylene (XLPE) cables are selected as the research object and first aged at 160 °C for 24, 72, 144, 240, and 360 h, and the corresponding frequency-domain spectrum (FDS) curves are obtained by experiment. Then, the DRT curves are solved by mathematical transformation, and the characteristic parameters are extracted. Finally, the quantitative relationship between aging duration and characteristic parameters was established by fitting a logistic model. The results show that DRT can adequately reflect different types of polarization information, and its characteristic parameters can be applied to study the aging state of XLPE cables. The innovation of this article is to propose a possible method based on DRT to study relaxation polarization.

Abstract: The wind system over the seas southeast of Asia (SSEA) plays an important role in China's climate variation. In this paper, ERS scatterometer winds covering the period from January 2000 to December 2000 and the area of 2–411N, 105–1301E were analyzed with a distance-weighting interpolation method and the monthly mean distribution of the sea surface wind speed were given. The seasonal characteristics of winds in the SSEA were analyzed. Based on WAVEWATCH III model, distribution of significant wave height was calculated.

Abstract: The wind system over the China seas plays an important role in climate variation there. In this paper, ERS-2 scatterometer winds covering the period of 1998 and the area of 25–411N, 117–1301E were analyzed and compared to NCEP winds and buoy winds in the same period and location, to assess how well the ERS-2 data reflect the real wind regime, at least for this area. The results indicated that ERS-2 scatterometer winds are closer to buoy observations than NCEP winds. In addition, a new wind-wave growth relation was applied to calculate wave parameters.

Abstract: This study deals with the development of statistical modeling for water wave surface elevation by using a method that combines a dynamic solution with random process statistics. Ocean wave data taken from four NOAA (National Oceanic and Atmospheric Administration) buoys moored in the northeast Pacific were used to validate the model. The results indicated that the nonlinear probability density distribution of ocean wave surface elevation derived from the model described the measurements much better than Gaussian distribution and Longuet-Higgins distribution.

It is traditionally assumed that the relationship between wave steepness and wave age is independent of the wind wave growth state. In fact, the traditional relationship can not describe the whole course of wind wave growth. This paper assumes that the relationship between wave steepness and wave age changes with the variety of dimensionless fetch. Based on the relationship proposed by Hou and Wen (1990), a new relationship in the course of wind wave growth is revealed. Comparisons between the present study and other previous relationships show that this new relationship explains better the observations than the other existing relationships. In the case of small fetch, wave age value increases more quickly than other models while it is in opposition to that in the case of large fetch. The result in present paper can clearly reflect the whole course of wind wave growth, it is an improvement for traditional results.

An MOM2 based 3-dimentional prognostic baroclinic Z-ordinate model was established to study the circulation in eastern China seas, considering the topography, inflow and outflow on the open boundary, wind stress, temperature and salinity exchange on the sea surface. The results were consistent with observation and showed that the Kuroshio intrudes in large scale into the East China Sea continental shelf East China, during which its water is exchanged ceaselessly with outer sea water along Ryukyu Island. The Tsushima Warm Current is derived from several sources, a branch of the Kuroshio, part of the Taiwan Warm Current, and Yellow Sea mixed water coming from the west of Cheju Island. The water from the west of Cheju Island contributes approximately 13% of the Isushima Warm Current total transport through the Korea Strait. The circulation in the Bohai Sea and Yellow Sea is basically cyclonic circulation, and is comprised of coastal currents and the Yellow Sea Warm Current. Besides simulation of the real circulation, numerical experiments were conducted to study the dynamic mechanism. The numerical experiments indicated that wind directly drives the East China Sea and Yellow Sea Coastal Currents, and strengthens the Korea Coastal Current and Yellow Sea Warm Current. In the no wind case, the kinetic energy of the coastal current area and main YSWC area is only 1% of that of the wind case. Numerical experiments also showed that the Tsushima Warm Current is of great importance to the formation of the Korea Coastal Current and Yellow Sea Warm Current.

Abstract Sedimentological, cyclic‐stratigraphic, paleomagnetic, and clay‐mineralogical studies on the early Oligocene Yaxicuo Group in the Hoh Xil Basin, the largest Cenozoic sedimentary basin in the hinterland of the Tibetan Plateau, provide abundant information of paleoclimate changes. A 350‐m thick section in the middle‐lower Yaxicuo Group was analyzed to reveal the climatic history that occurred in the Hoh Xil region during the early Oligocene interval 31.30‐30.35 Ma, dated with the paleomagnetic chronostratigraphy. The results indicate that arid and cold climate dominated the Hoh Xil region during the early Oligocene in general, being related to the global cooling and drying events that occurred in the earliest Oligocene. Within this period, relatively warm and wet climate accompanied by strong tectonic activity occurred in the 31.05–30.75 Ma interval; while arid and cold climate and relatively inactive tectonics occurred in the 31.30–31.05 and 30.75‐30.35 Ma intervals. Furthermore, spectral analyses of high‐temporal resolution paleoclimatic records show orbital periods including eccentricity, obliquity, and precession. It is concluded that paleoclimate changes during the early Oligocene in the Hoh Xil region were forced by both tectonic activity and orbital periods.

We report new results from our paleomagnetic studies of the Inner Mongolia autonomous region in northeastern China and the Xinjiang autonomous region in northwestern China. Primary magnetizations are isolated in Tertiary, Cretaceous, Late Jurassic and Late Permian rocks and secondary components of magnetization of Late Jurassic and Recent ages are seen in strata of Inner Mongolia. Western Junggar Basin and part of the Tarim block, suffered widespread complete tectono-thermal remagnetization at about 280 Ma (Permian). The paleomagnetic evidence suggests that the sampled areas in Inner Mongolia have been part of the North China Block at least since Late Permian time and the Junggar block collided with the Tarim block by Late Permian time. Our own paleomagnetic results together with available data from other parts of eastern Eurasia, suggest a tectonic model in which Kazakhstan, Europe and Siberia collided with each other and formed the Europe-Siberia-Kazakhstan plate (EUR-SIB-KAZ) in Late Permian time. To the east, Mongolia (= Outer Mongolia), Inner Mongolia and the North China Block were also wedged together forming the Mongolia-North China plate (MON-NC) by this time. These two composite continental plates were not a stable unit in the Late Permian. The geometrical relationship of the paleomagnetic poles for these two plates suggests that collision initially occurred in the Late Permian near the western end (50°N, 75°E) of the Southern Siberian Fold Belt and progressed eastward as the MON-NC plate rotated and clockwise about 117° relative to the EUR-SIB-KAZ plate during the Early Mesozoic. Suturing and rotation were probably complete by the Late Jurassic. Significant relative motion between the Tarim and Siberia blocks continued from Early Triassic to Late Jurassic, as Tarim moved northeastward 1400 km relative to Siberia.