中国留学人员创业园分布及产业特征

以《中国留学人员创业年鉴》为基础数据,采用GIS空间分析技术,运用核密度估计法、L函数和最近邻层次聚类分析等方法,分析2006~2015年中国留学人员创业园空间分布规律以及园区产业集聚特征,结果表明：中国留学人员创业园集聚特征显著,而且随着时间的推移,其多中心趋势明显,集聚规模迅速增大,集聚强度呈“先升后降,但总体增大”趋势;主要集聚于长三角、京津冀和珠三角等地区,尤以前两者最显著,且三大集聚区的集聚强度与集聚规模差异明显,其中长三角留创园的集聚规模最大,京津冀集聚强度最高,而珠三角则比较复杂,其在很小空间尺度范围内服从集聚分布,而在较大空间尺度范围内则服从随机分布;基于不同主导产业的中国留学人员创业园依然集中于长三角、京津冀和珠三角等地区,其主导产业分布格局则差异显著,规律性不强。     

Direct Climatic Effect of Dust Aerosol in the NCAR Community Atmosphere Model Version 3 （CAM3）

Direct climate responses to dust shortwave and longwave radiative forcing (RF) are studied using the NCAR Community Atmosphere Model Version 3 (CAM3). The simulated RF at the top of the atmosphere (TOA) is-0.45 W m-2 in the solar spectrum and +0.09 W m-2 in the thermal spectrum on a global average. The magnitude of surface RF is larger than the TOA forcing, with global mean shortwave forcing of-1.76 W m-2 and longwave forcing of +0.31 W m-2 . As a result, dust aerosol causes the absorption of 1.1 W m-2 in t...     

基于MODIS数据的雪面温度遥感反演

On the basis of simplification of the Planck function in a low temperature range, this paper revises the practical split-window algorithm and presents a method for retrieving snow surface temperature （Ts） based on MODIS data in the middle-latitude region. The application of this method in Qinghai Lake region reveals that it is feasible for the retrieval of Ts. Results of correlation analysis indicate that there was strong negative relationship between Ts and altitude. By analyzing three typical areas in which land cover was relatively homogenous, this paper discusses the relationship between Ts and normalized difference snow index （NDSI） and then presents a new concept named ＂NDSI-Ts space＂.     

直接测定内蒙古腮林忽洞组碳酸盐岩Pb－Pb同位素年龄

碳酸盐岩Ｐｂ－Ｐｂ同位素测年是地质年代学一个新的分支,本文利用这一技术,直接测定了内蒙古地区腮林忽洞组年龄,是本区首次直接获得地质年龄,不仅为碳酸盐地区确定地质年代提供了新的方法,同时对本区地层研究提供了新的数据。本文期待引起同行讨论,使这一新方法在地质研究应用中臻于完善。     

东海陆扰海域铜、铅、锌、镉重金属排海通量及海洋环境容量估算

汇总并分析了20世纪80年代初以来东海陆扰海域重金属排海通量年变化规律及主要来源,应用多介质海洋环境中重金属迁移-转化模型,估算了东海陆扰海域重金属海洋环境容量。20世纪80年代初以来,东海陆扰海域铜、铅、锌、镉排海总量整体上呈不对称的倒"U"形变化趋势,基本符合"环境库兹涅茨曲线",20世纪90年代达到最大值,当前排海总量仍高于20世纪80年代初期的水平。东海陆扰海域铜、铅、锌、镉污染物主要来源于以河流为主的陆源排放,其中88.0%左右来源于河流排放,7.5%左右来源于排污口,只有4.5%左右来源于大气沉降。长江流域排海通量占东海陆扰海域排海总量的比例最大,平均为92.4%左右,钱塘江流域平均只有3.9%左右,闽江流域平均只有3.7%左右。东海陆扰海域铜、铅、锌、镉污染物海洋环境容量分别约为17.0,4.7,113.1,0.71 kt/a。当前铅、锌、镉污染物排海总量没有超过东海陆扰海域海洋环境容量,但铜的排海总量超过其海洋环境容量大约8%。     

高速公路通道下沉开裂治理实践

河南省省道323线登封市大冶镇一段公路软弱地基以及路面出现不均匀沉降,通道箱涵开裂,边坡为欠稳定边坡。将事故路段分为4个区域进行加固治理。通过采用注浆加固路基基础、设置坡面排水系统、提高地基的承载能力等治理措施,保证了道路的通行能力。     

Parameterization of the Absorption of the H_2O Continuum,CO_2,O_2,and Other Trace Gases in the Fu-Liou Solar Radiation Program

The absorption properties of the water vapor continuum and a number of weak bands for H2O, O2, CO2, CO, N2O, CH4, and O3 in the solar spectrum are incorporated into the Fu-Liou radiation parameterization program by using the correlated k-distribution method (CKD) for the sorting of absorption lines. The overlap absorption of the H2O lines and the H2O continuum (2500-14500 cm-1) are treated by taking the two gases as a single-mixture gas in transmittance calculations. Furthermore, in order to optimize the computation efforts, CO2 and CH4 in the spectral region 2850-5250 cm-1 are taken as a new single-mixture gas as well. For overlap involving other absorption lines in the Fu-Liou spectral bands, the authors adopt the multiplication rule for transmittance computations under which the absorption spectra for two gases are assumed to be uncorrelated. Compared to the line-by-line (LBL) computation, it is shown that the errors in fluxes introduced by these two approaches within the context of the CKD method are small and less than 0.48% for the H2O line and continuum in the 2500-14500 cm-1 solar spectral region, -1% for H2O (line) H2O (continuum) CO2 CH4 in the spectral region 2850-5250 cm-1, and -1.5% for H2O (line) H2O (continuum) O2 in the 7700-14500 cm-1 spectral region. Analysis also demonstrates that the multiplication rule over a spectral interval as wide as 6800 cm-1 can produce acceptable errors with a maximum percentage value of about 2% in reference to the LBL calculation. Addition of the preceding gases increases the absorption of solar radiation under all sky conditions. For clear sky, the increase in instantaneous solar absorption is about 9%-13% (~12 W m~2) among which the H2O continuum produces the largest increase, while the contributions from O2 and CO2 rank second and third, respectively. In cloudy sky, the addition of absorption amounts to about 6-9 W m-2. The new, improved program with the incorporation of the preceding gases produces a smaller solar absorption in clouds due to the reduced solar flux reaching the cloud top.     

Influence of Approach Channel on Wave Propagation with Varying Incident Angles

- The variation of the amplitude of waves with varying incident angles when waves propagate through a typical approach channel is discussed by a numerical calculation method, the result of which shows that the influence of the channel on wave propagation is obvious. When the wave propagation direction is in coincidence with the channel axis, the wave amplitude ratio will decrease with the increase of propagation distance. When the incident angle is 15 - 30 , there appears an area of larger wave amplitude ratio on the side slope facing the waves, but at the another side, the wave amplitude ratio is generally small, indicating that the channel has a shielding effect. When waves propagate across the channel perpendicularly, the wave amplitude ratio can be calculated with the shallow water coefficient.