孙中山先生的西北观

吾国人之"西北观",在近代中国有一大转变焉。察国人以现代化观念全面审视西北、规划并进行之西北建设,端赖孙中山先生之倡导。中山先生从中国经济发展的全局考虑,视西北开发为未来经济腾飞之希望;从边疆稳定、国家统一、民族团结和少数民族地区的进步繁荣考虑,力主及早并大规模的开发西北;他还借鉴先进国家经验,把建设现代化国家之交通网作为开发西北的前提任务。其思想对后人的教益,文献资料可征。在20世纪30年代以后掀起的近代开发西北的舆论和实践中,处处反映着孙中山思想的深刻影响,本文将一一论列之。

Thermohaline finestructure observed near the northern Philippine coast

Using hydrographic measurements from three recent surveys in the western tropical Pacific, this study revealed the existence and general features of thermohaline finestructure near the northem Philippine coast. Pronounced finestructttres were detected in the layers of the North Pacific Tropical Water （NPTW） and the North Pacific Intermediate Water （NPIW） during all three cruises and shown to be mainly thermohaline intrusions. Characteristics of the intrusions were further investigated with spiciness curvature and salinity anomaly methods. The vertical scale of the intrusions was 20-50 m and 50-100 m in the NPTW and NPIW layers, respectively. Within the NPTW layer, the Turner angle distribution and correlation between salinity and density anomalies suggested that diffusive convection between surface fresh water and subsurface saline water played an important role in the development and maintenance of the intrusions. In addition, connection between thermohaline finestructure and larger-scale oceanic processes was explored using historical hydrographic data. The results reveal that the salinity field and the distribution of the intrusions in this region were largely determined by mesoscale eddies. As a result of eddy stirring, both isopycnal and diapycnal temperature/salinity gradients were strengthened, which gave rise to the development of thermohaline intrusions. The intrusions acted to enhance heat and salt fluxes and resulted in the mixing of water masses being more efficient. By linking mesoscale eddy stirring to micro-scale diffusion, thermohaline finestructure plays a vital role in the ocean energy cascade and water mass conversion in the northern Philippine Sea.

Assessment of Dust Aerosol Optical Depth and Shortwave Radiative Forcing over the Northwest Pacific Ocean in Spring Based on Satellite Observations

Dust aerosol optical depth (AOD) and its ac-companying shortwave radiative forcing (RF) are usually simulated by numerical models.Here,by using 9 months of Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol product data in combination with Clouds and the Earth's Radiant Energy System Single Scanner Footprint (CERES/SSF) data,dust AOD and its shortwave RF were estimated over the cloud-free north-west (NW) Pacific Ocean in the springs of 2004,2005,and 2006.The results showed that in this region,the mean dust AOD and its shortwave RF were 0.10 and 5.51 W m 2,respectively.In order to validate the dust AOD de-rived by MODIS,results from the Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model were also used here.The correlation coefficient between the monthly averaged dust AOD derived by MODIS measurements and the model simulation results was approximately 0.53.Since the estimates of the dust AOD and its shortwave RF obtained in this study are based mainly on satellite data,they offer a good reference for numerical models.

Climatic variation of tropical cyclones affecting China during the past 50 years

Trends of the tropical cyclones (TCs) influence on China and its four subregions,namely the South China (SC),East China (EC),Northeast China (NEC),and China's inland area (CI),are detected by applying quantile regression to the CMA-STI tropical cyclone best track and related severe wind and precipitation observation datasets.The results indicate that in the past 50 years,the number of TCs affecting China and its four subregions has remained steady,except that the frequency in extremely active years has decreased not only in China as a whole,but also in NEC.In addition,TC activity is found to have weakened over the northwest South China Sea,Guangdong,and Shandong Peninsula.However,the most important changes in seasonality are found in the first quartiles of the number of days of TCs affecting CI.While the extreme values of sustained winds all have decreasing trends,the extreme values of wind gusts are completely different not only among different orders of extreme values,but also among different subregions.However,the trends of extreme TC rainfall,namely the maximum storm precipitation and the maximum 1-h precipitation,are not significant.

Microstructures and deformation mechanisms of hornblende in Guandi complex,the Western Hills,Beijing

Multiple methods were applied to study the deformation characteristics of hornblende in Archean plagioamphibolite mylonite from the Western Hills(Beijing),including optical microscopy(OM),electron backscatter diffraction(EBSD),transmission electron microscopy(TEM),and electron probe microanalysis(EPMA).The hornblendes are σ and δ type porphyroclasts with the new-born needle shaped grains as their tails.The analysis of lattice preferred orientation(LPO) of both the porphyroclasts and the new-born grains shows that the main slip system of the deformed hornblende is(100)<001>,suggesting that the fabric characteristics of new-born grains inherit that of porphyroclasts.Sub-microstructures show the porphyroclast core is dominated by dislocation tangle,little or no dislocations in the new-born grains,and the subgrains confined by dislocations in the transition zone between porphyroclasts and new-born grains.By using plagioclase-hornblende geothermometry and hornblende geobarometry,the estimated temperature and pressure of porphyroclasts are 675.3-702.9℃ and 0.29-0.41 GPa and those of new-born grains are 614.1-679.0℃ and 0.11-0.31 GPa.The bulging recrystallization is summarized as deformation mechanisms of hornblende by the discussions of the microstructures,EBSD fabric,sub-microstructures,and the deformed temperature and pressure.