次天气尺度及中尺度暴雨系统研究进展

回顾了75年来中国科学院大气物理研究所科研人员在次天气尺度及中尺度暴雨系统领域的研究工作,这些领域主要包括暴雨、中尺度低空急流、低涡、梅雨锋结构及梅雨锋生、对称不稳定和涡层不稳定以及暴雨等灾害天气的天气动力学及数值模拟研究等;总结了在次天气尺度及中尺度暴雨系统研究的不同时期所取得的成就以及这些成就在防止和减轻中尺度暴雨灾害方面所起到的重要作用.     

A comparison of three image-object methods for the multiscale analysis of landscape structure

Within the conceptual framework of Complex Systems, we discuss the importance and challenges in extracting and linking multiscale objects from high-resolution remote sensing imagery to improve the monitoring, modeling and management of complex landscapes. In particular, we emphasize that remote sensing data are a particular case of the modifiable areal unit problem (MAUP) and describe how image-objects provide a way to reduce this problem. We then hypothesize that multiscale analysis should be guided by the intrinsic scale of the dominant landscape objects composing a scene and describe three different multiscale image-processing techniques with the potential to achieve this. Each of these techniques, i.e., Fractal Net Evolution Approach (FNEA), Linear Scale-Space and Blob-Feature Detection (SS), and Multiscale Object-Specific Analysis (MOSA), facilitates the multiscale pattern analysis, exploration and hierarchical linking of image-objects based on methods that derive spatially explicit multiscale contextual information from a single resolution of remote sensing imagery. We then outline the weaknesses and strengths of each technique and provide strategies for their improvement.     

模块化模糊神经网络的数值预报产品释用预报研究

综合应用预报量自身时间序列的拓展,数值预报产品和模块化模糊神经网络方法,进行了一种新的数值预报产品释用预报研究。将这种新方法与常规的数值预报产品完全预报(PP)方法进行了对比试验。结果表明,这种模块化模糊神经网络数值预报产品释用预报方法比PP预报方法的预报精度显著提高。并且,通过对预报模型“过拟合”现象的研究发现,这种模块化模糊神经网络的数值预报产品释用预报模型具有很好的泛化性能。     

东北大部旱情缓解 粤闽局地暴雨成灾──1997年5月

东北大部旱情缓解粤闽局地暴雨成灾—１９９７年５月—徐良炎（国家气候中心，北京１０００８１）５月份，东北大部、华北北部及黄淮等地普降喜雨，旱情缓解；西北东部、华北西部等地降水偏少，旱情持续或发展。南方大部地区雨水比较调匀，无大范围旱涝发生，但华南局地遭...     

湘鄂赣二叠纪岩相古地理研究

湘鄂赣二叠纪沉积盆地是在华南陆块基础上发育而成，具有扬子克拉通北缘被动大陆边缘盆地，扬子克拉通盆地，湘赣板内拉张盆地和华夏克拉通边缘盆地等四类。根据古暴露等标志，建立了各类盆地的沉积层序，并进行了区域对比。     

内陆待开发地区产业发展模式探讨——以内蒙古为例

以内蒙古为例，探讨了内陆待开发地区的产业发展模式，内陆待开发地区经济发展的主要制约因素是缺乏资金，缺乏技术，缺乏人才，因此，其经济发展必须有选择，有重点地优先发展部分行业。一般说来，待开发的内陆地区其经济发展必须以资源优势为依托，以市场为导向，开发优质名牌产品，发展优势产业，建设主导产业，带动地区经济的起飞。     

The Organization of Production in High Technology Industries: An Empirical Assessment*

Recent attention given to the concept of vertical integration and disintegration of production processes has identified the existence of a continuum, with small, flexibly specialized producers at one end and large, mass production units at the other end. Firms along the continuum constantly strive for the optimum combination of economies of scale and scope. This paper attempts to identify the organizational characteristics of high technology firms in one industrial complex of the U.S. Manufacturing Belt. A principal components analysis is performed on a number of theoretically relevant variables for a sample of high technology establishments in Northeast Ohio. The results indicate that the region contains a variety of organizational forms ranging from isolated workshops to large, vertically integrated assembly plants. These findings conform to expectations derived from recent conceptualizations in the literature. Additional empirical research will further enhance understanding of the processes that shape the organization of production in territorial complexes.     

三角洲平原上网结河的发育与聚煤作用

龙潭组上段（２４＃煤顶板到１２＃煤）是盘县地区含煤最好的层段，对该区西北部本段地层的研究表明其中发育有网结河体系。河道沉积由多层叠置的鞋带状砂体组成，湿地沉积主要由菱铁质泥质岩夹薄层板状细砂岩（决口扇沉积）和煤组成。河流的发育和聚煤作用都显示幕式性，可能主要受海平面变化的控制。网结状河道被认为是海侵期对低位下切河谷充填过程中经侧向冲裂水道并相互连通形成的；稳定、连续的厚煤层发育于河道大范围废弃后的海侵晚期，其次是高水位早期。     

Generating fracture networks using iterated function systems

In order to model flow and transport in fractured rocks it is important to know the geometry of the fracture network. A stochastic approach is commonly used to generate a synthetic fracture network from the statistics measured at a natural fracture network. The approach presented herein is able to incorporate the structures found in a natural fracture network into the synthetic fracture network. These synthetic fracture networks are the images generated by Iterated Function Systems (IFS) as introduced by Barnsley (1988). The conditions these IFS have to fulfil to determine images resembling fracture networks and the effects of their parameters on the images are discussed. It is possible to define the parameters of the IFS in order to generate some properties of a fracture network. The image of an IFS consists of many single points and has to be suitably processed for further use.     

Genesis and distribution of mineral waters as a consequence of recent lithospheric dynamics: the Rhenish Massif,Central Europe

Three major, interdependent processes control the genesis and distribution of mineral and thermal waters in the Rhenish Massif, Central Europe: (a) Magmatic processes in the upper mantle provide most of the CO₂ to produce bicarbonate waters in shallow aquifers. (b) Extension of the brittle upper crust enables the ascent of sodium chloride waters. (c) Uplift and erosion shape the massif's relief, which determines the extent of flow systems and the distribution of thermal springs. The chemistry of mineral waters further depends on the aquifers' mineral composition. A comprehensive set of hydrological, chemical, tectonic and geophysical data on the Rhenish Massif has been compiled. It was used to classify the mineral waters and to map the spatial distribution of water properties. The composition of cuttings from several representative wells producing different water types shows that the hydrothermal alteration of the aquifer rocks consists mainly of kaolinization of chlorite and dissolution of feldspar. Numerical transport simulations favour two modes of groundwater flow: topography-driven flow and the pressure-driven ascent of basement brines along active faults. Thermal convection is less important.