Retrieving volume FeO and TiO_2 abundances of lunar regolith with CE-2 CELMS data using BPNN method

The volume FeO and TiO_2 abundances(FTAs) of lunar regolith can be more important for understanding the geological evolution of the Moon compared to the optical and gamma-ray results. In this paper, the volume FTAs are retrieved with microwave sounder(CELMS) data from the Chang'E-2 satellite using the back propagation neural network(BPNN) method. Firstly, a three-layered BPNN network with five-dimensional input is constructed by taking nonlinearity into account. Then, the brightness temperature(TB) and surface slope are set as the inputs and the volume FTAs are set as the outputs of the BPNN network.Thereafter, the BPNN network is trained with the corresponding parameters collected from Apollo, Luna,and Surveyor missions. Finally, the volume FTAs are retrieved with the trained BPNN network using the four-channel TBderived from the CELMS data and the surface slope estimated from Lunar Orbiter Laser Altimeter(LOLA) data. The rationality of the retrieved FTAs is verified by comparing with the Clementine UV-VIS results and Lunar Prospector(LP) GRS results. The retrieved volume FTAs enable us to re-evaluate the geological features of the lunar surface. Several important results are as follows. Firstly, very-low-Ti(<1.5 wt.%) basalts are the most spatially abundant, and the surfaces with TiO_2> 5 wt.% constitute less than 10% of the maria. Also, two linear relationships occur between the FeO abundance(FA) and the TiO_2 abundance before and after the threshold, 16 wt.% for FA. Secondly, a new perspective on mare volcanism is derived with the volume FTAs in several important mare basins, although this conclusion should be verified with more sources of data. Thirdly, FTAs in the lunar regolith change with depth to the uppermost surface,and the change is complex over the lunar surface. Finally, the distribution of volume FTAs hints that the highlands crust is probably homogeneous, at least in terms of the microwave thermophysical parameters.     

基于卫星测高数据的萨德湿地水位变化研究

以萨德湿地为例,使用ENVISAT和Jason2卫星测高数据利用改进的阈值法进行回波重定,反演萨德湿地水位。结果显示:萨德湿地的恒定水域水位变化规律。通过对比萨德湿地和维多利亚湖的水位变化可以发现,维多利亚湖对萨德湿地南部水域水位有巨大的影响,且影响与人类活动(尤其是欧文瀑布大坝的水能发电)有很大的关系,而位于大坝下游的阿尔伯特湖水位变化和萨德湿地南部水域水位变化有很强的相关性。     

福建近海五种主要捕捞作业适宜捕捞力量的研究

本文根据福建省定置、拖、围、刺、钓五种捕捞作业在本省近海的捕捞力量和渔获量,并以１９９４年单位功率的渔捞效率为基准进行逐年捕捞力量的标准化,应用Ｓｃｈａｅｆｅｒ和Ｆｏｘ两同电脑分别估算它们的ｆＭＳＹ和ＭＳＹ。结果两处在算的ｆＭＳＹ和ＭＳＹ的平均值是：定置网为８．９０尤明等３７．４１万ｔ;推网为５５．８８万ＫＷ,３５．５１万ｔ;为桃围网为７．１２万ＫＷ,１０．０６万ｔ;刺网为１５．１９万ＫＷ,９．５     

长期非平稳荷载调谐质量减振阻尼器优化设计

研究外荷载为长期非平稳随机过程。考虑长期荷载的特性 ,采用 1个概率谱密度函数来反映长期非平稳随机荷载及其特征 ;概率谱密度函数是基于大量的一般谱密度函数的统计特性获得。以延长结构的抗疲劳使用寿命为目标函数 ,提出了调谐质量减振阻尼器的优化设计方法 ,这在实际工程中有着极为广阔的应用前景。本文旨在从理论上发展长期非平稳随机荷载作用下调谐质量减振阻尼器的优化设计方法 ;文中采用长期波浪实测数据 ,给出了 1个数值算例说明整个设计过程。     

一种新的海洋经济微藻——粉核油球藻

以Pinguiococcuspyrenoidosus CCMP 2004为实验藻种,研究分析了藻粉的基本生化组成和培养周期中PUFAs组成与含量的动态变化.结果表明,该藻的蛋白质量分数为37.54%,粗脂肪为27.45%,其中PUFAs包括18:2,18:3,18:4,20:4(AA,Arachidonic acid),20:5(EPA,Eicosapentaenoic acid),22:4(DTA,Docosatetraenoic acid)和22:6(DHA,Docosahexaenoic acid).该藻PUFAs的组成特征是EPA含量高,质量分数为20.93%,其他不饱和脂肪酸(16 : 3,16:4,18:3和18 : 4)的含量极微.分析结果显示粉核油球藻的营养价值较高,是一种新的具有商业化开发潜力的海洋微藻.     

日本、美国等国家防震减灾法律法规制度比较研究

日本、美国作为全球地震高发区,分别制定了相对完善的法律法规体系,并积累了防震减灾制度建设方面的丰富经验。本文首先收集与梳理日本、美国等国家相关的防震减灾法制体系。分析日、美等国家政府部门管理、社会管理及全民参与的体制与机制。以日本为例,分析日本在防灾对策强化区的基本思路。最后从我国的基本国情出发,提出适合我国重点监视防御区工作的建议,即:1重防区的确定、相应的法律法规制定及信息的公布;2提高重防区的监测、预测、房屋抗震和应急救援能力;3提高公众防灾抗灾意识;4增加地震预测、烈度速报与预警系统方面的财政投入;5地震保险业的推广。     

近海型含煤岩系沉积学及层序地层学研究进展

层序地层学是近20年来发展起来的一门新的方法学科,并在聚煤作用分析中得到广泛应用。作者就近海型含煤岩系沉积学研究历史以及煤系层序地层学研究方法及有关问题进行探讨,认为近海环境的聚煤作用实际上是海平面(基准面)上升过程中发生的,同时提出煤层厚度受泥炭堆积速率与可容空间增加速率的控制：靠陆一侧冲积平原和三角洲平原沉积环境中,厚煤层主要出现在最大海泛面位置;而靠海一侧障壁-潟湖或碳酸盐岩台地沉积环境中,厚煤层主要出现在初始海泛面的位置;但就整个三级复合层序来说,层序中厚度最大、分布最广的煤层主要分布于可容空间增加速率最大的最大海泛面附近的位置。对于中国晚古生代近海型煤系中常见的“根土岩-煤-石灰岩”序列,聚煤作用发生于海相石灰岩“滞后时段”,即在海侵之后、海相石灰岩层真正沉积下来之前的时段,这一时段可容空间增加速率与泥炭堆积速率平衡,有利于聚煤作用发生。     

安哥拉下刚果盆地吉拉索尔深水油田

吉拉索尔油田位于西非安哥拉17号深水区块,水深1200～1400m,距安哥拉海岸150km。1996年发现,2001年产油,是安哥拉投入开发的第一个深水油田。油田面积约140km2,地质储量约为15.5×108bbl,可采储量约7.25×108bbl,为轻质油。油田所在的下刚果盆地主要经历了裂谷期、过渡期和热沉降期三个阶段的构造演化,相应沉积了裂谷期陆相地层、过渡期蒸发岩层和热沉降期海相地层。主要烃源岩为下白垩统Bucomazi组湖相页岩,有机质丰度高,类型好,成熟度适中,为很好的烃源岩。盆地深水区主要储层为上渐新统—中新统河道充填浊积砂岩复合体,砂岩固结差,物性良好。吉拉索尔油田主要由几个河道浊积砂岩复合体叠置组成,其中夹几个薄层席状砂岩,复合体之间被海相泥页岩分隔。上覆第三系泥岩为其主要盖层。     

Parameter estimation for a karst aquifer with unknown thickness using the genetic algorithm method

The combination of ecological fragility and agricultural activity in the loess hilly–gully regions of western China has received broad environmental concerns. In this region, rainfall and soil moisture can fatally influence crop production under dry land farming. In this study, field experiments were conducted, from March 2001 to September 2005, to demonstrate the variation of soil moisture and fertilizer contents at different depths in slope and terraced lands, and to evaluate the ecological impacts and economic benefits in the terraced land of Loess Plateau. The results of both field test and Grey model (GM) calculation show that the terraced land, as compared to the sloping land, in the agricultural area of the Loess Plateau tends to store and retain much water, promoting more favorable interactions between water and fertilizer. During the months from March to June of the year with less rainfall, the water supply for crop growth is mainly derived from the deep storage of soil moisture accumulated from July to September of the previous year. The field experiments indicate that the crop yield of the 3-year-old terraced lands was 27% higher than that of the sloping lands with slopes greater than 10°, and that the crop yield can increase by 27.07 to 52.78% in the following cultivation years. In particular, potato was found to be more drought-resistant than winter wheat, thus it is more suitable for the arid and semi-arid Loess Plateau regions.     

SOUTHERN BOUNDARY FORCING RELATIVE TO GENESIS, MAINTENANCE AND OSCILLATION OF A SUBTROPICAL HIGH*

A nonlinear critical layer and a Kelvin cat's eye excited thereupon are simulated through four schemes in the context of a nonlinear quasi-geostrophic barotropic vorticity equation model with forced stationary wave acting along the southern boundary to investigate effects of tropical steady forcing on the genesis,maintenance and oscillation of a subtropical high(STH).Evidence suggests that the southern forcing is responsible for the planetary quasi-steady anticyclonic Kelvin cat's eye-form flow field inside the nonlinear critical layer,with the eye shifting,vigor and shape changing quite similar to the behaviors of a summer STH,in striking contrast to the northern stationary forcing.As such,the southern boundary-caused cat's eye is likely to be an even more important mechanism for STH genesis and evolution.In addition,a physical mechanism is introduced for quasi-steady planetary wave moving through the critical layer at subtropical latitudes.