放马滩秦简日书“星度”篇初探

备受学界瞩目的《天水放马滩秦简》一书已于近期出版,其中刊布了被称为＂星度＂的12枚竹简,可独立成篇。这是目前所见有关二十八宿距度及逐月日躔之次的最早记录。

卫星星座设计概述

调研了国内外星座设计的现状和进展，概要介绍了理想星座、实际应用星座的组网方法，星座的稳定性及保持方法。

Modified algorithm of combined GPS/GLONASS precise point positioning for applications in open-pit mines

A modified algorithm of combined GPS/GLONASS precise point positioning （GG-PPP） was developed by decreasing the number of unknowns to be estimated so that accurate position solutions can be achieved in the case of less number of visible satellites. The system time difference between GPS and GLONASS （STDGG） and zenith tropospheric delay （ZTD） values were firstly estimated in an open sky condition using the traditional GG-PPP algorithm. Then, they were used as a priori known values in the modified algorithm instead of estimating them as unknowns. The proposed algorithm was tested using observations collected at BJFS station in a simulated open-pit mine environment. The results show that the position filter converges much faster to a stable value in all three coordinate components using the modified algorithm than using the traditional algorithm. The modified algorithm achieves higher positioning accuracy as well. The accuracy improvement in the horizontal direction and vertical direction reaches 69% and 95% at a satellite elevation mask angle of 50°, respectively.

Ocean surface currents retrieval based on the satellite remote sensing data

The ocean surface currents are reconstructed from the satellite remote sensing data containing altimeter-derived sea surface height and QuikSCAT satellite-derived wind data. Based on the method proposed by Lagerloef, a global weekly 0.5°×0.5°ocean surface current product was obtained over the period 2000 - 2008 by combining the geostrophic currents estimated from sea surface height with Ekman current estimated from the wind stress. Particularly, weight functions were introduced when calculating the Ekman currents to eliminate the discontinuity near 25°S and 25°N. These satellite-derived currents have been compared with TAO current meter and the SCUD product, respectively. The comparison showed that satellite-derived currents not only could capture the characteristics of ocean surface currents but also had high accuracy and reliability. The result showed that this innovatory method was effective.

图的拟拉普拉斯永久多项式

设Ｇ是一简单无向图，Ｃ（Ｇ）表示Ｇ的关联矩阵，Ｑ（Ｇ）＝Ｃ（Ｇ）Ｃ（Ｇ）ｔ称为Ｇ的拟拉普拉斯矩阵．该文研究了永久多项式ｐｅｒ［ｘＩ－Ｑ（Ｇ）］．

Effects of salinity on growth and feeding of juvenile Starry flounder (Platichthys stellatus)

The survival rate, feeding, growth of juvenile Starry flounder were studied at different salinities. The results showed that when the fish was directly translated from salinity of 32 to 0 and more than 0, the survival rate was 100% in 96 hours. If the fish was acclimatized, it was still 100% in 42 days. The fish at the salinity of 0 - 16 grew faster than others; feeding rate varied as salinity changed, and the highest one was at salinity of 32 and the lowest one was at the salinity of 16. As to feed conversion efficiency, the highest one was at the salinity of 16, and the lowest one was at the salinity of 24. There were no significant differences among the treatments （P＆gt;0.05）. It was found that low salinity benefited for recovering albinism.

Prediction of Petroleum Prospect in the South Yellow Sea Basin Using Satellite Remote Sensing

Using satellite remote sensing to measure the sea surface temperature of the East China Sea Shelf Basin can serve the purpose of predicting the petroleum prospect in the South Yellow Sea Basin. The satellite thermal infrared temperature anomaly area always repeats in the same position as the proved oil prospect area in the East China Sea Shelf Basin, and coincides well with both the CH4 content curve at the water-atmosphere interface and the seafloor geochemical anomaly. The sea surface temperature anomaly areas of the South Yellow Sea Basin in the satellite remote sensing image go banded along 123030, in the S-N direction, and naturally follow the aeromagnetically interpreted eastern nose-type uplift that shows a S-N strike. The north and south ends of the eastern nose are considered as good oil prospect areas because temperature anomaly often occurs there.

On simulation of precise orbit determination of HY-2 with centimeter precision based on satellite-borne GPS technique

The HY-2 satellite carrying a satellite-borne GPS receiver is the first Chinese radar altimeter satellite, whose radial orbit determination precision must reach the centimeter level. Now HY-2 is in the test phase so that the observations are not openly released. In order to study the precise orbit determination precision and procedure for HY-2 based on the satellite- borne GPS technique, the satellite-borne GPS data are simulated in this paper. The HY-2 satellite-borne GPS antenna can receive at least seven GPS satellites each epoch, which can validate the GPS receiver and antenna design. What＇s more, the precise orbit determination processing flow is given and precise orbit determination experiments are conducted using the HY-2-borne GPS data with both the reduced-dynamic method and the kinematic geometry method. With the 1 and 3 mm phase data random errors, the radial orbit determination precision can achieve the centimeter level using these two methods and the kinematic orbit accuracy is slightly lower than that of the reduced-dynamic orbit. The earth gravity field model is an important factor which seriously affects the precise orbit determination of altimeter satellites. The reduced-dynamic orbit determination experiments are made with different earth gravity field models, such as EIGEN2, EGM96, TEG4, and GEMT3. Using a large number of high precision satellite-bome GPS data, the HY-2 precise orbit determination can reach the centimeter level with commonly used earth gravity field models up to above 50 degrees and orders.

Sea Surface Roughness Derivation from Wind Speed Estimated by Satellite Altimeter

For open sea conditions the sea surface roughness is described as a function of surface stress and wind speed over sea surface by Charnock relation. The sea surface roughnessn in the North-west Pacific Ocean is derived successfully using wind speed data estimated by the TOPEX satellite altimeter. From the results we find that： （1） the mean sea surface roughness in winter is greater than in summer; （2） compared with other sea areas, the sea surface roughness in the sea area east of Japan （ N30°- 40°, E135°- 150°） is larger than in other sea areas; （3） sea surface roughness in the South China Sea changes more greatly than that in the Bohai Sea, Yellow Sea and East China Sea.

Genetic Analysis and Linkage Mapping in a Resource Pig Population Using Microsatellite Markers

The use of markers and linkage map construction are important for QTL mapping in pigs. In this article, the genetic characteristics were studied and the linkage map was constructed in a pig resource population including 214 individuals by typing 39 microsatellite marker loci on Sus scrofa chromosomes, SSC4, SSC6, SSC7, SSC8, and SSC13. Results indicated that the average allele number, the average observed beterozygosity （Ho）, and the average polymorphism information content （PIC） in F1 and F2 population were 3.2, 0.528, 0.463 and 3.2, 0.496, 0.447, respectively. In the pig resource population, the average informative meiosis （IM） was 217.4 （44-316）, and the average linkage map length between the two sexes on the five chromosomes were 172.3 cM （SSC4）, 168.7 cM （SSC6）, 191.7 cM （SSC7）, 197.3 cM （SSC8）, and 178.3 cM （SSC13）. The orders of microsatellite marker loci in the linkage maps were identical to, but the length was greater than, those of USDA-MARC reference map. The results of this research showed the genetic relationship and genetic characteristics of the microsatellite markers in the pig resource family population, and the linkage map could be used to for QTL mapping in the subsequent study.

Noisy-power dissipation and efficiency in NiO/Fe_2O_3 wet grinding by planetary ball mill

The relationship between the efficiency of NiO/Fe2O3 wet grinding and noisy-power dissipation was studied. The optimal grinding parameters were found as: a slurry water content of 64.10%-85.47%, ball number ratio of 360/20, revolution speed of 300.9 r/min, powder-filling ratio of 10.88%, ball-filling ratio of 20.53%-23.88%, and grinding time of approximately 6 h. The discrete element method(DEM) was employed to analyze relationship between the noisy-power dissipation and the grinding efficiency, and equations describing the relationship were derived. The mean particle size of the ground powder decreased with a decrease in the degree of noisy-power dissipation, while the grinding efficiency and the amount of specific impact power used decreased with an increase in the degree of noisy-power dissipation.

Optimization model of GNSS/pseudolites structure design for open-pit mine positioning

A new pseudolites （PLs） structure optimization model of global navigation satellite system （GNSS）/PLs integration positioning system used in deep open-pit mine was presented. Position dilution of precision （Pdop） and reliability were selected as the optimization indicators to build a multi-objective optimization model to decide the optimum PLs location. A scheme was designed by establishing a four-dimensional model taking azimuth （a）, elevation angle （e） and epoch （t） of satellites as the input independent variables and Pdop as the dependent variable to calculate the optimum PLs location zone considering the real circumstances. And then the ultimate PLs location can be fixed by testing the curves of Pdop along time. A field collected Trimble R8 GPS data set in China University of Mining and Technology （CUMT） campus was used for the model test to show the effectiveness, and the proposed PLs optimum design scheme was used at the west open-pit mine of Fushun mining group Co., Ltd., in China, better Pdop and reliability have been achieved for the integration system. Both experiments show that the proposed scheme is excellent in designing GNSS/PLs system which is helpful for improving the performance of the positioning system and reducing the cost.

An Assessment of Urban Heat Island Effect using Remote Sensing Data

Characteristics of urban heat island （UHI） effect and its cause are investigated by using MODIS data in April 2004. Surface parameters from the MODIS data have surface temperature （ts） albedo（α）, and normalized difference vegetation index （NDVI）. Their heterogeneities over urban and rural area are analyzed based on land cover classification, and their relations are also presented in order to explain the UHI effect. The results show that there exists obvious the UHI effect. Ts over urban areas are by 10.83 % higher than those over rural area, and NDVI and α over urban area are by 62 % and 18.75 % less than those over rural area, respectively. Surface temperature has significantly negative correlation with NDVI and their correlation coefficient is -0.73. Correlation between NDVI and albedo is determined by the spectrum of light. Difference in vegetation cover is the primary cause of the UHI effect.

The Kuroshio Transport East of Taiwan and the Sea Surface Height Anomaly from the Interior Ocean

The relationship between the Kuroshio transport to the east of Taiwan and the SSHA (Sea Surface Height Anomaly) field is studied based on the World Ocean Circulation Experiment (WOCE) PCM-1 moored current meter array observation, the satellite altimeter data from the MSLA (Map of Sea Level Anomaly) products merged with the ERS and TOPEX/POSEIDON (T/P) data sets, and the WOCE satellite-tracked drifting buoy data. It is confirmed that the Kuroshio transport across PCM-1 array highly correlates with the SSHA upstream (22°-24°N, 121.75°-124°E). The SSHA is not locally generated by the developed Kuroshio meandering but is from the interior ocean and is propagating westward or northwestward. During the period from October 1992 to January 1998, two events of the northwestward propagating negative SSHA occurred, during which the SSHA merged into the Kuroshio and caused the remarkable low transport events in contrast to the normal westward propagating negative SSHA. It is also shown that the lower Kuroshio transport event would be generated in different ways. The negative anomaly in the upstream of PCM-1 array can reduce the Kuroshio transport by either offshore or onshore Kuroshio meandering. The positive anomaly, which is strong enough to detour the Kuroshio, can cause an offshore meandering and a low transport event at the PCM-1 array.

Comparative analysis of significant wave height between a new Southern Ocean buoy and satellite altimeter

In-situ observation is restricted by the strong wind and waves in the Southern Ocean.A Westerlies EnvironmentalMonitoring Buoy(WEMB)was firstly deployed in the Southern Ocean during China’s 35th Antarctic Expedition,facilitating further understanding of the oceanic environmental characteristics of this region.With the develop-ment of technology and the improvement of data processing methods,the accuracy of satellite altimeter productsis constantly improved,thus making it possible to inspect and evaluate the in-situ observation data.Based on theL3 products of multiple satellite altimeters,this paper analyzes and corrects the significant wave height(SWH)data of WEMB by means of data matching,error statistics,and linear least-squares fitting.Through this study,the authors obtained the following results.The effect of gravitational acceleration changes with latitude on SWHaccuracy is fairly small.Due to the low response of WEMB to high-frequency waves,there is a systematic devia-tion.A feasible correction method is therefore proposed to improve the SWH accuracy of WEMB.The temporalvariation of the corrected SWH is highly consistent with that of the 10 m wind during the observation period,and its average value reaches 3.8 m.

Identifying Global Monsoon Troughs and Global Atmospheric Centers of Action on a Pentad Scale

Using two datasets of global pentad grid precipitation and global 850 hPa geopotential height during 1979-2007,this study identified global monsoon troughs and global atmospheric centers of action (ACAs) on a pentad scale.The global monsoon troughs consist of planetary-scale monsoon troughs and peninsula-scale monsoon troughs.Forced by seasonal variations in solar radiation,the inter-tropical convergence zones (ITCZs) represent the planetary-scale monsoon troughs,which are active and shift over the tropical North Pacific,the tropical North Atlantic,and the tropical South Indian oceans.The peninsula-scale monsoon troughs are originated from regional land-sea topography and varied with contrasts in seasonal land-sea surface temperatures and precipitation.During the boreal summer,five peninsula-scale troughs and one planetary-scale trough are distributed in the Asia-Northwest Pacific (NWP) region.In total,22 troughs,nine monsoon troughs,and 19 ACAs in the lower troposphere were identified.Relevant ACAs may be useful in constructing regional monsoon and circulation indices.

Numerical simulation of wave fi eld in the South China Sea using WAVEWATCH III

Wave fields of the South China Sea （SCS） from 1976 to 2005 were simulated using WAVEWATCH III by inputting high-resolution reanalysis wind field datasets assimilated from several meteorological data sources. Comparisons of wave heights between WAVEWATCH III and TOPEX/Poseidon altimeter and buoy data show a good agreement. Our results show seasonal variation of wave direction as follows： 1. During the summer monsoon （April-September）, waves from south occur from April through September in the southern SCS region, which prevail taking about 40% of the time; 2. During the winter monsoon （December-March）, waves from northeast prevail throughout the SCS for 56% of the period; 3. The dominant wave direction in SCS is NE. The seasonal variation of wave height Hs in SCS shows that in spring, Hs〉l m in the central SCS region and is less than 1 m in other areas. In summer, Hs is higher than in spring. During September- November, influenced by tropical cyclones, Hs is mostly higher than 1 m. East of Hainan Island, Hs〉2 m. In winter, Hs reaches its maximum value influenced by the north-east monsoon, and heights over 2 m are found over a large part of SCS. Finally, we calculated the extreme wave parameters in SCS and found that the extreme wind speed and wave height for the 100-year return period for SCS peaked at 45 m/s and 19 m, respectively, SE of Hainan Island and decreased from north to south.

Small Target Extraction Based on Independent Component Analysis for Hyperspectral Imagery

A small target detection approach based on independent component analysis for hyperspectral data is put forward. In this algorithm, firstly the fast independent component analysis(FICA) is used to collect target information hided in high-dimensional data and projects them into low-dimensional space.Secondly, the feature images are selected with kurtosis .At last, small targets are extracted with histogram image segmentation which has been labeled by skewness.

On Urban Heat Island of Beijng Based on Landsat TM Data

Land surface temperature (LST) of Beijing area was retrieved from Landsat TM thermal band data utilizing a radiative transfer equation and the urban heat island (HUI) effects of Beijing and its relationship with land cover and normalized difference vegetation index (NDVI) were discussed. The result of LST showed that the urban LST was evidently higher than the suburban one. The average urban LST was found to 4.5 ℃ and 9 ℃ higher than the suburban and outer suburban temperature, respectively, which demonstrated the prominent UHI effects in Beijing. Prominent negative correlation between LST and NDVI was found in the urban area, which suggested the low percent vegetation cover in the urban area was the main cause of the urban heat island.

High Precision Orbit Determination of CHAMP Satellite

The precision orbit determination of challenging minisatellite payload(CHAMP) satellite was done based on position and navigation data analyst(PANDA) software which is developed in Wuhan University, using the onboard GPS data of year 2002 from day 126 to 131. The orbit accuracy was assessed by analyzing the difference from GFZ post-processed science orbits (PSO), the GPS carrier and pseudo-range data residuals and the satellite laser ranging (SLR) residuals.