基于主体功能区约束的大气污染物总量控制目标分配研究

考虑经济发展水平、污染物排放现状、污染物治理水平、空气质量,特别是国家主体功能区环境目标约束等因素,构建大气污染物排放总量分配的指标体系,用改进的等比例分配方法对2015年国家SO2,NOx总量控制目标进行区域分配。分配结果表明:SO2和NOx削减量大的省份主要集中在华北平原及其周围地区,这些地区污染物排放量大、空气质量较差;削减比例较大的地区主要集中在西部地区以及北京、天津2个直辖市,这些地区单位GDP能耗高、工业污染物去除率低、空气质量差;削减量相对较小的地区主要集中在西南和南部一些省份;削减比例较小的地区主要集中在中南部和南部几个省份,这些地区污染物排放量相对较少,空气质量好于其他省份。     

Research on Creep Deformation and Control Mechanism of Weak Surrounding Rock in Super Large Section Tunnel

Geotechnical and Geological Engineering - In order to solve the difficulties of creep deformation of surrounding rock in super large section tunnel, taking Letuan tunnel of Binlai expressway, a...     

Combined perturbation on near-earth satellite orbits

Using a semi-analytical method, we have obtained a first-order solution of the equations of motion of near-Earth satellites under the combined perturbing effect due to Earth's figure and air drag.     

On the hawking evaporation of Dirac particles in Kerr-Newman spacetime

We have obtained a solution of the Dirac equation near the horizon of a Kerr-Newman black hole and compared it with the solution of the Klein-Gordon equation. We first generalized the work of LIU Liao and XU Dian-yan for a quasi-extreme Kerr black hole to a quasi-extreme Kerr-Newman black hole, then further generalized to a general Kerr-Newman black hole, and thereby verified that the Dirac particles emitted by a general Kerr-Newman black hole do have a black-body energy spectrum.     

Distribution of suspended particulate matter in the northern Bohai Bay in summer and its relation with thermocline

Field observations of suspended particulate matter (SPM) in the Bohai Bay, China have not been widely reported. The aim of this paper is to describe the horizontal and vertical distribution of mass and volume concentrations of SPM, respectively, based on observed data at 312 stations in the northern Bohai Bay during summer of 2006. A numerical model ECOMSED coupled with a sediment transport module was also established to further discuss the mechanism of the thermocline effect on the vertical distribution of SPM. The mass concentrations of SPM exhibited high inshore values and low offshore values in the horizontal distribution; while in the vertical direction, characteristics of the volume concentration of SPM can be divided into two types: one with a sharp peak at depth of 10–15 m and another without. The peak value at the depth of the thermocline was resulted from concentrated phytoplankton. A numerical experiment further displayed that the thermocline can also prevent particles from being resuspended upward.     

海冰形变对北极冬季CICE模式冰厚模拟结果的影响

海冰数值模式是研究海冰动力热力状态参量及之间联系的有效途径。目前对冰厚数值模拟结果的分析远远少于对海冰范围/面积和密集度的研究,对冰速与海冰形变对冰厚分布影响的研究也尚欠缺。本文利用Los Alamos sea ice model（CICE）海冰模式模拟了1980−2018年的北极海冰变化,并使用遥感、同化冰厚数据进行比对验证,分析了模拟冰速和海冰形变对冰厚的影响,计算了冰速的散度和切变偏差对冰厚偏差的贡献。结果显示,CICE对北极70°N以北区域平均冰厚和冰速的年际变化模拟基本合理,但模拟的平均冰厚和冰速多年变化趋势均小于同化数据的变化率;模拟和观测冰厚的空间分布差异与冰速和形变率的偏差有密切联系,主要表现为波弗特海的正偏差和北极中央区至弗拉姆海峡的负偏差。泛北极区域散度和切变偏差在3月之前对冰厚偏差的贡献在13%～16%之间变化,3−4月则由16%跃变至27%。散度偏差主导了11月、12月波弗特海区域的冰厚正偏差,切变偏差主导了冬季加拿大群岛以北海域和穿极流区域的冰厚负偏差。     

Using a New Sky Brightness Monitor to Observe the Annular Solar Eclipse on 15 January 2010

For the future development of Chinese Giant Solar Telescope (CGST) in Western China, a new sky brightness monitor (SBM) has been produced for the site survey for CGST. To critically examine the performance and sensitivity of SBM, we used it in the observation of the annular solar eclipse in Dali City, Yunnan, on 15 January 2010. The observation met good weather conditions with an almost clear sky during the eclipse. The SBM measurement translates into the solar illuminance changes at a level of 2.4×10^?4 I?s^?1 during the eclipse. The time of the minimal sky brightness in the field of view (FOV) is found consistent with the time of maximum eclipse. Two local sky regions in the FOV are chosen to make a time series of the calibrated skylight profiles. The evolution of the sky brightness thus calibrated also shows good consistency with the eclipse, particularly between the second and the third contacts. The minimal sky brightness in each local sky region took place within half a minute from the corresponding predicted contact time. Such small time delays were mainly caused by occasional cirri. The minimal sky brightness measured during the eclipse is a few millionths of I _?? with standard deviation of 0.11 millionths of I _??. The observation supports that the single-scattering process (optically thin conditions) is the main contributor to the atmospheric scattering. We have demonstrated that many important aerosol optical parameters can be deduced from our data. We conclude that the new SBM is a sensitive sky photometer that can be used for our CGST and coronagraph site surveys.     

Correction of the temperature effect in calibration of a solar radio telescope

This work analyzes the annual fluctuation of the observation data of the Mingantu Solar radio Telescope(MST) in S, C and X bands. It is found that the data vary with local air temperature as the logarithmic attenuation of equipment increases with temperature and frequency. A simplified and effective calibration method is proposed, which is used to calibrate the MST data in 2018–2020, while the correction coefficients are calculated from data in 2018–2019. For S, C and X bands, the root mean square errors of one polarization are 2.7, 5.7 and 20 sfu, and the relative errors are 4%, 6% and 8% respectively. The calibration of MUSER and SBRS spectra is also performed. The relative errors of MUSER at 1700 MHz,SBRS at 2800 MHz, 3050 MHz and 3350 MHz are 8%, 8%, 11% and 10% respectively. We found that several factors may affect the calibration accuracy, especially at X-band. The method is expected to work for other radio telescopes with similar design.