特大地震对震源邻区的增(减)震作用的研究

通过研究中国大陆1910年以来8级以上特大地震和国外几组典型特大地震对震源邻近区域的影响,发现特大地震往往发生在断裂带上,一组或一次特大地震可能使发震断裂部分破裂,而未破裂断裂的构造应力可能增大,又成为大震的空段,该空段短时间内可能会发生大震(起到增震作用);反之,发震断裂完全破裂或没有大震空段,震源邻近区域构造应力可能减小,短时间可能不会发生大震(起到减震作用)。依据这一结果,可对特大地震发生后震源邻近区域的后续大震作短、中期预测。     

前汛期北江洪水过程水汽汇与河水流量的关系

本文分析了１９８０－１９８４年４－６月和１９９４年６月洪水过程北江流域的大气水汽汇特征及其与河水流量的关系。结果表明：前汛期洪水过程的前期大乞一般连续存在超过一定值的较强水汽汇，时间为１周左右，洪水的发生是强水汽汇连续产生的径流的积累所致；北江流域洪水期水汽汇的极大峰一般比石角站的洪峰流量超前２天左右，本文结果为洪水的预报提供一条新思路。     

美国现行的地基气象观测系统

美国气象部门在近十几年对其地基气象观测系统进行了新的一轮现代化的更新换代.目前,这一过程已基本完成.现对该系统的主要情况和特点作简要的介绍.     

大气中的包络Rossby孤立波——纬度效应的作用

本文进一步对旋转正压大气中的包络Rossby孤立波进行了研究，结果发现当Rossby波的波数m（m为纬向波数）满足1≤m≤2时，旋转正压大气中才存在包络Rossby孤立波，并且只有m＝2的包络Rossby孤立波才具有阻塞高压的结构。我们还对这种m＝２的包络Rossby孤立波随纬度变化的持续性进行了计算，得到了许多结果。     

华南沿海地区太阳直接辐射、能见度及大气气溶胶变化特征分析

分析了中国华南地区福州、广州、海口、南宁等地1961～1990年太阳直接辐射总量、日照时数、总云量、大气能见度和地面水汽压等资料,并利用这些资料反演了该地区大气气溶胶的光学厚度值。结果表明：近30年来,华南地区太阳直接辐射总量和日照时数呈明显下降趋势。与60年代相比,80年代各站太阳直接辐射总量的年平均值均下降20%以上,其中广州下降29.2%;日照时数,广州减少了1.1 h,福州1 h,南宁0.9 h,海口0.5 h。分析发现,造成下降的原因不是由于云量或大气中水汽含量的变化,而是由于地面能见度的明显减小和大气气溶胶的增加。4站中,14时地面能见度均以夏季最好,最高值出现在7月;而地面能见度最差的季节海口、南宁两站在冬季,福州和广州两站在春季3、4月份。相比较而言,海口能见度最好,福州和南宁次之,广州最差。4站大气气溶胶光学厚度值的大小、年及季节变化与地面能见度有密切的关系,但两者不尽一致,因此,在研究气溶胶的辐射和气候效应时必须合理地考虑中高层大气气溶胶的分布。     

Multidimensional-unified topological relations computation: a hierarchical geometric algebra-based approach

This article presents a geometric algebra-based model for topological relation computation. This computational model is composed of three major components: the Grassmann structure preserving hierarchical multivector-tree representation (MVTree), multidimensional unified operators for intersection relation computation, and the judgement rules for assembling the intersections into topological relations. With this model, the intersection relations between the different dimensional objects (nodes at different levels) are computed using the Tree Meet operator. The meet operation between two arbitrary objects is accomplished by transforming the computation into the meet product between each pair of MVTree nodes, which produces a series of intersection relations in the form of MVTree. This intersection tree is then processed through a set of judgement rules to determine the topological relations between two objects in the hierarchy. Case studies of topological relations between two triangles in 3D space are employed to illustrate the model. The results show that with the new model, the topological relations can be computed in a simple way without referring to dimension. This dimensionless way of computing topological relations from geographic data is significant given the increased dimensionality of geographic information in the digital era.     

双循环新格局下重庆市城镇化发展动力与实现路径

源于时代之变而构筑的双循环新发展格局是市场经济条件下多尺度空间输出理论与劳动地域大分工的“叠加”,为新型城镇化发展带来新的动力源泉。为了揭示这种影响,首先将科技创新和制度改革这2个城镇化发展动力外生变量内生化,构建基于“四维驱动力模型+创新力+制度力”的城镇化动力因子分析框架,结合主成分回归模型对2000年以来重庆市城镇化发展动力进行分析,并据此引入波特的“钻石模型”对其城镇化发展路径进行系统思考。结果表明：1）纳入动力因子体系的创新力和制度力对重庆市城镇化发展产生显著的正向驱动效应,其中创新力表现最为明显。2）重庆市城镇化发展是“六维力”共同作用的结果,但市场力和行政力依然是最主要的驱动力;其次是创新力、内源力和外向力,其中创新力对城镇化发展的驱动效应已在阶段2(2010—2018年)超越行政力的作用效应;最后是制度力;间接反映重庆市城镇化本身是一个内生作用的过程,构筑“以国内大循环为主体、国内国际双循环相互促进”新发展格局具有客观必然性和前瞻性。3）基于波特“钻石模型”分析指出：重庆市存在增长极体量小、市场购买力不足、产品低端化、同质化现象严重等问题,并据此从发展高级生产要素、创造...     

Characteristics of high arsenic groundwater in Hetao Basin, Inner Mongolia, northern China

It is well known that the Hetao Basin is one of the most seriously arsenic-affected groundwater areas in China. In order to understand the characteristics of high arsenic(As) groundwater in the Basin, a brief overview of arsenic in groundwater follows. High arsenic in the Basin commonly occurs in shallow groundwater and the total arsenic concentrations range from 0.58 to 572 μg/L(average 99.73 μg/L), exceeding the maximum mandated value of 10 μg/L for drinking water in China; As(Ш) is the predominant species. The regional distribution pattern of arsenic in the groundwater increases from south/southeast to north/northwest. Hangjinhouqi and Wuyuan counties are considered as the most seriously affected areas, with high incidences of endemic arsenicosic diseases in the Hetao Basin. High groundwater arsenic correlates with the increase of well depth. Previous studies proposed that groundwater arsenic in the Basin is mainly originated from desorption of some natural solid materials in the sediments, under reducing condition. Generally, reducing condition is believed to be the primary factor for arsenic releasing from the sediment to groundwater in the region. Under inorganic or bacterial processes, Fe2O3 changes to Fe S and arsenic adsorbed to Fe(OH)3 dissolves into groundwater, and As(V) is reduced to As(Ш). Besides, reducing environments, groundwater hydraulic gradients, organic matter, p H, evapotranspiration, and soil texture are presumed to be the predominant factors that control arsenic mobilization.     

基于PPT战略的广东省乐昌市生态旅游扶贫模式探讨

以贫困人口受益为出发点,基于有利于贫困人口发展的旅游(Pro-Poor Tourism,PPT)战略,以广东省乐昌市为例,开展适用于中国南方林区生态旅游扶贫开发的发展模式和旅游扶贫产业的发展路径研究.结果表明:1)政府部门、旅游企业、乡村社区和非营利社会组织都应在提升贫困人口参与度、减轻贫困和生态保护方面承担责任,具体...