Three-dimensional analysis of ozone and PM<Subscript>2.5</Subscript> distributions obtained by observations of tethered balloon and unmanned aerial vehicle in Shanghai,China

A lightweight unmanned aerial vehicle (UAV) and a tethered balloon platform were jointly used to investigate three-dimensional distributions of ozone and PM_2.5 concentrations within the lower troposphere (1000 m) at a localized coastal area in Shanghai, China. Eight tethered balloon soundings and three UAV flights were conducted on May 25, 2016. Generalized additive models (GAMs) were used to quantitatively describe the relationships between air pollutants and other obtained parameters. Field observations showed that large variations were captured both in the vertical and horizontal distributions of ozone and PM_2.5 concentrations. Significant stratified layers of ozone and PM_2.5 concentrations as well as wind directions were observed throughout the day. Estimated bulk Richardson numbers indicate that the vertical mixing of air masses within the lower troposphere were heavily suppressed throughout the day, leading to much higher concentrations of ozone and PM_2.5 in the planetary boundary layer (PBL). The NO and NO₂ concentrations in the experimental field were much lower than that in the urban area of Shanghai and demonstrated totally different vertical distribution patterns from that of ozone and PM_2.5. This indicates that aged air masses of different sources were transported to the experimental field at different heights. Results derived from the GAMs showed that the aggregate impact of the selected variables for the vertical variations can explain 94.3% of the variance in ozone and 94.5% in PM_2.5. Air temperature, relative humidity and atmospheric pressure had the strongest effects on the variations of ozone and PM_2.5. As for the horizontal variations, the GAMs can explain 56.3% of the variance in ozone and 57.6% in PM_2.5. The strongest effect on ozone was related to air temperature, while PM_2.5 was related to relative humidity. The output of GAMs also implied that fine aerosol particles were in the stage of growth in the experimental field, which is different from ozone (aged air parcels of ozone). Geographical parameters influenced the horizontal variations of ozone and PM_2.5 concentrations by changing underlying surface types. The differences of thermodynamic properties between land and sea resulted in quick changes of PBL height, air temperature and dew point over the coastal area, which was linked to the extent of vertical mixing at different locations. The results of GAMs can be used to analyze the sources and formation mechanisms of ozone and PM_2.5 pollutions at a localized area.     

Submersion simulation in a typical debris flow watershed of Jianzhuangchuan catchment,Loess Plateau

Debris flow is one of the most serious and frequent geological disasters that occur in the Loess Plateau. The outbreak of a debris flow is sudden, ferocious, swift, and destructive. The characteristics and mechanism of debris flow were explored in this study via survey, numerical simulation, and simulation analysis in a Loess Plateau area (Huangling County, Shaanxi Province, China). Numerical models and formulas corresponding to the occurrence and movement mechanism were established based on the HEC-RAS, HEC-GeoRAS, and SWAT results. The range of debris flow deposition was determined through capturing the debris flow free surface. A hydrological model and critical rainfall threshold were determined in order to provide technical support for debris flow forecasting in the Loess Plateau. The results suggest that 10-year floods do not submerge any portion of the basin. One village area was affected by the 100-year flood (total area of 0.648 km²) while four villages areas were submerged by the 1000-year flood (total area of 1.39 km²). The method presented here may provide a reliable scientific basis for mitigating loss due to debris flow hazards.     

中国贵金属矿床的基本成矿规律与找矿方向

通过对近年来贵金属矿床勘查进展及其主要类型、主要成矿时代、主要矿集区等的分析与归纳,总结了中国金矿床、银矿床和铂族元素矿床的基本成矿规律,并提出它们各自的找矿方向。中国金矿床类型多,主要形成于中生代和新生代,集中在胶东、辽东、华北地台边缘、小秦岭、阿尔泰、金沙江-红河断裂带、台湾和东南沿海、滇黔桂、陕甘川及长江、黑龙江等主要水系的上游,金矿的找矿方向包括:①老矿区的"探边摸底"和"攻深找盲";②新矿集区的典型研究与采选冶技术改进;③综合利用技术的创新将使相当多的表外矿变为当前可开采的矿床;④新区勘查;⑤加强成矿系列、成矿体系和成矿规律的研究,以理论指导找矿并综合评价。中国银矿以伴生银矿为主,主要形成于中生代和新生代,变质岩、岩浆岩和沉积岩均可容矿,造山带和盆地区的构造破碎带尤其值得重视。当前需要加强对锰矿区含银性和Mn异常区的研究,尤其是中国东部中新生代盆地区断裂带与Mn、Ag化探异常吻合地区,应该综合评价。中国铂族元素矿床可以分为岩浆型、沉积型和热液型三大类,可形成于从前寒武纪到新生代的各个时代,至少构成8个重要成矿远景区(带),重点放在康滇地轴和二叠纪末期峨眉地幔柱影响到的地区,但华北地台老基底中的原生矿及其周边的砂矿不可忽视。     

工作状态下梁及桥梁模态与损伤识别的新方法

工作状态下桥梁结构的模态参数识别是桥梁损伤识别的重要环节,考虑桥梁检测的实用性,桥梁检测一般应建立在环境激励的基础上,已有的环境激励下模态参数识别的方法对模态频率的识别的精度较高,而对位移模态的识别则误差较大。提出了一种利用移动质量块在不同位置时对桥梁的模态频率进行多次测量,用各次测得的频率值确定位移模态的新方法,使得位移模态识别的精度接近频率识别的精度,建立了该方法的初步模型,推导了频率与位移模态关系的理论公式,并通过数值模拟对该方法的有效性进行了说明。     

南极普里兹湾海域铀系同位素的分布

本文报道了南极普里兹湾海域U、2 2 6Ra、2 1 0 Pb、2 1 0 Po的分布以及2 34U/2 38U和2 1 0 Po/2 1 0 Pb放射性比值。研究结果表明 ,该海域表层水中的铀同位素分布基本均匀 ,铀含量范围为1 3 2 8- 1 4 2 0 μmol·m- 3,平均值为 ( 1 3.82± 0 .2 9) μmol·m- 3,2 34U/2 38U平均放射性比值为1 1 4± 0 0 3。铀含量与盐度之间存在良好的相关性 ,其相关系数达 0 895。该海域溶解态2 2 6Ra比活度范围为 1 37- 1 78Bq·m- 3,平均值为 1 5 5Bq·m- 3;颗粒态 2 2 6Ra比活度范围为0 0 0 6- 0 0 35Bq·m- 3,平均值为 0 0 1 5Bq·m- 3;2 1 0 Po比活度 0 80- 1 5 2Bq·m- 3,平均 1 1 4Bq·m- 3;2 1 0 Pb比活度 1 34- 2 1 5Bq·m- 3,平均 1 66Bq·m- 3;2 1 0 Po/2 1 0 Pb的放射性比值0 5 5- 0 84,平均 0 69。并对2 1 0 Po和2 1 0 Pb的不平衡作了讨论。还研究了 1个站位溶解态和颗粒态2 2 6Ra、2 1 0 Pb的深度分布及2 1 0 Pb在两相中的分配     

农业重大气象灾害监测预警与控制技术研究

1.北方农业低温冷害监测预警技术研究 "北方农业低温冷害监测预警技术研究"2007年在以下4个方面取得了较显著的进展.     

我国城市更新中的权益博弈研究述评

城市更新是城市发展的一种重要方式,其关键和难点在于平衡利益相关者之间的权益博弈。在城市化快速发展时期,我国便出现了大规模的城市更新,这使得我国城市更新中的权益博弈形成了独特的模式与特征,较之于西方发达国家也更加复杂。文章认为随着我国城市更新研究的不断深入,在权益博弈研究领域取得了一定的成果,但也存在一些问题与不足,如对博弈主体间的关系研究不足、对城市更新中的“社会运动”现象研究不够,未来的研究需要综合运用多学科理论,注重典型个案的深入研究,逐步构建出合乎中国国情的城市更新权益博弈理论。     

胜利东二号露天矿6煤层直接液化性能评价

基于褐煤直接液化特性与煤性质的关系,从煤岩组分和煤质基本性质出发,结合前人对与褐煤直接液化相关的煤岩组分和煤质指标研究成果,通过采样测试与收集数据,探讨了胜利煤田东二号露天矿6煤层煤岩组分、灰分、挥发分、H/C原子比对其直接液化的影响,提出了褐煤作为直接液化的指标要求范围。结果表明:该煤层活性组分(腐植组和稳定组)含量较高,挥发分含量大于35%、H/C原子大部分大于0. 70、浮煤灰分大部分小于10%,符合液化指标要求,可作为较理想的直接液化原料煤。     

Metallogenic and Metamorphic Age of the Hongtoushan Copper–Zinc Massive Sulfide Deposit,Liaoning Province,China

The Hongtoushan copper–zinc deposit is the only large Archean volcanogenic massive sulfide (VMS) deposit in China. This paper presents new information on the timing of metallogenesis and metamorphism of the deposit, including new cathodoluminescence (CL) images, and Th U^?1 and LA–ICP–MS U–Pb dating on zircons of the biotite–plagioclase gneiss and plagioclase–amphibole gneiss that host the deposit. The CL images and Th U^?1 ratios indicate that the zircons within the gneiss are of metamorphic origin. LA–ICP–MS dating of the plagioclase–amphibole gneiss yielded the upper intercept ages of 2549 Ma, and the biotite–plagioclase gneiss yielded the upper intercept ages of 2552 Ma and 2550 Ma correspondingly, indicating that the mineralization of the deposit occurred at around 2550 Ma. The rims of zircons within these host rocks yielded younger U–Pb ages at 2529, 2520 and 2515 Ma, identical to the age of felsic intrusive rocks in the study area. This suggests that the Hongtoushan VMS deposit underwent initial metamorphism and deformation at around 2520 Ma by the intrusion of granite magmas.     

Growth performance of larval and juvenile manila clam (<Emphasis Type="Italic">Ruditapes philippinarum</Emphasis>) from divergently selected individuals of a full-sib family

In this study, the method of divergent selection was employed to test the larval and juvenile growth performance within a full-sib family of Manila clam Ruditapes philippinarum. The 10% largest and 10% smallest clam individuals (on the basis of shell length) of a full-sib family were selected as parents for the fast and slow growing lines, respectively. The difference in shell length was significant among the three lines (fast, control, and slow) tested. The sequence of shell length were fast line > control line > slow line. The responses to selection, realized heritability, and genetic gain were 0.06%–0.81%, 0.04%–0.47% and 0.58%–18.89% in the fast direction, respectively; and were 0.14%–1.27%, 0.08%–0.73%, and 0.31%–49.03% in the slow direction, respectively. The results suggested that there was a large portion of additive genetic variance affecting the growth in the full-sib family. Selection in the fast direction within the full-sib family would greatly improve the growth of R. philippinarum.